harew1 adlı üyeden alıntı: mesajı görüntüle 
        Class Kategori_ek_yazi {
            private $fieldsInfo = [
        array(
            "label" => "Kategori Ek Yazı Alanı",
            "type" => "textarea",
            "description" => "",
            "placeholder" => "",
            "name" => "kategoriekyazialani",
            "id" => "KategoriEkYazi_fields[kategoriekyazialani]",
        ),
         ];
        
            public function __construct() {
        
                if ( is_admin() ) {
                    add_action("category_add_form_fields", [$this, "add_term_fields"], 10, 2);
                    add_action("category_edit_form_fields", [$this, "edit_term_fields"], 10, 2);
                    add_action("created_category", [$this, "save_meta"], 10, 2 );
                    add_action("edited_category", [$this, "update_meta"], 10, 2 );
                }
            }
        
        
            private function generate_table_html( $label, $field, $desc ) {
                return "<tr class='form-field'><th>$label</th><td>$field<p>$desc</p> </td></tr>";
            }
        
            private function generate_input_html($fieldtype, $field_id, $value="", $placeholder="") {
        
                switch ($fieldtype) {
                    case "text":
                    return "<input id='$field_id' $placeholder value='$value' size='40' type='$fieldtype' name='$field_id'/>";
                        break;
                    case "textarea":
                        return "<textarea $placeholder name='$field_id' id='$field_id' rows='5' cols='40'>$value</textarea>";
                        break;
                    default:
                        return;
                }
            }
        
        
            function add_term_fields() { // adding view
        
                $fields = $this->fieldsInfo; $html;
        
                foreach ($fields as $key=>$field) {
        
                    if(isset($field["placeholder"])) { $placeholder = "placeholder='".$field["placeholder"]."'"; }
                    else { $placeholder ='';}
                    $input = $this->generate_input_html($field["type"], $field["id"], "", $placeholder);
                    $html .= "<label for='".$field["id"]."'>".$field["label"]."</label>$input
                    <p>".$field["description"]."</p>";
                }
        
                $html = "<div class='form-field'>$html</div>";
        
                echo $html;
        
            }
        
            function edit_term_fields($term) { // edit view
        
                $fields = $this->fieldsInfo; $html;
        
                foreach ($fields as $key=>$field) {
        
                    $value = get_term_meta($term->term_id, $field["name"], true);
        
                    if(isset($field["placeholder"])) {
                        $placeholder =  "placeholder='".$field["placeholder"]."'";
                    } else { $placeholder ="";}
        
                    $label = "<label for='".$field["id"]."'>".$field["label"]."</label>";
                    $input = $this->generate_input_html($field["type"], $field["id"], $value, $placeholder);
                    $html .= $this->generate_table_html($label, $input, $field["description"]);
                }
        
                echo $html;
                
            }
        
            function save_meta($term_id) {
                if( isset( $_POST["KategoriEkYazi_fields"] ) ) {
                    foreach ($_POST["KategoriEkYazi_fields"] as $key => $value) {
                        update_term_meta($term_id, $key, sanitize_text_field($value));  
                    }
                }
            }
        
            function update_meta($term_id){
                if( isset( $_POST["KategoriEkYazi_fields"] ) ) {
                    foreach ($_POST["KategoriEkYazi_fields"] as $key => $value) {
                        update_term_meta($term_id, $key, sanitize_text_field($value));
                    }
                }
            }
        }
        
        if (class_exists("Kategori_ek_yazi")) {
            new Kategori_ek_yazi;
        };
Yukarıdaki kodlar fazlasıyla işinizi görecektir.

get_term_meta('kategori_id_buraya_gelecek', 'kategoriekyazialani ', true) // Veri Çağırma
Aceleyle yazdım kaba taslak istediğiniz şey yukardaki kodlardır kendinize göre düzenleyip kullanırsınız
Emeğin, yardımların için teşekkür ederim.
Kodu kullanmaya çalıştığımda bir kaç hata aldım.
Araştırmalarım sonucu amacımı birebir karşılayan bir fonksiyon buldum.
İhtiyacı olan arkadaşlar tema lokasyonunuzun içinde bulunan "functions.php" dosyasının en altına ekleyerek kullanabilirsiniz.

Kaynak

// 1. Display field on "Add new product category" admin page
 
add_action( 'product_cat_add_form_fields', 'bbloomer_wp_editor_add', 10, 2 );
 
function bbloomer_wp_editor_add() {
    ?>
    <div class="form-field">
        <label for="seconddesc"><?php echo __( 'Second Description', 'woocommerce' ); ?></label>
       
      <?php
      $settings = array(
         'textarea_name' => 'seconddesc',
         'quicktags' => array( 'buttons' => 'em,strong,link' ),
         'tinymce' => array(
            'theme_advanced_buttons1' => 'bold,italic,strikethrough,separator,bullist,numlist,separator,blockquote,separator,justifyleft,justifycenter,justifyright,separator,link,unlink,separator,undo,redo,separator',
            'theme_advanced_buttons2' => '',
         ),
         'editor_css' => '<style>#wp-excerpt-editor-container .wp-editor-area{height:175px; width:100%;}</style>',
      );
 
      wp_editor( '', 'seconddesc', $settings );
      ?>
       
        <p class="description"><?php echo __( 'This is the description that goes BELOW products on the category page', 'woocommerce' ); ?></p>
    </div>
    <?php
}
 
// ---------------
// 2. Display field on "Edit product category" admin page
 
add_action( 'product_cat_edit_form_fields', 'bbloomer_wp_editor_edit', 10, 2 );
 
function bbloomer_wp_editor_edit( $term ) {
    $second_desc = htmlspecialchars_decode( get_woocommerce_term_meta( $term->term_id, 'seconddesc', true ) );
    ?>
    <tr class="form-field">
        <th scope="row" valign="top"><label for="second-desc"><?php echo __( 'Second Description', 'woocommerce' ); ?></label></th>
        <td>
            <?php
          
         $settings = array(
            'textarea_name' => 'seconddesc',
            'quicktags' => array( 'buttons' => 'em,strong,link' ),
            'tinymce' => array(
               'theme_advanced_buttons1' => 'bold,italic,strikethrough,separator,bullist,numlist,separator,blockquote,separator,justifyleft,justifycenter,justifyright,separator,link,unlink,separator,undo,redo,separator',
               'theme_advanced_buttons2' => '',
            ),
            'editor_css' => '<style>#wp-excerpt-editor-container .wp-editor-area{height:175px; width:100%;}</style>',
         );
 
         wp_editor( $second_desc, 'seconddesc', $settings );
         ?>
       
            <p class="description"><?php echo __( 'This is the description that goes BELOW products on the category page', 'woocommerce' ); ?></p>
        </td>
    </tr>
    <?php
}
 
// ---------------
// 3. Save field @ admin page
 
add_action( 'edit_term', 'bbloomer_save_wp_editor', 10, 3 );
add_action( 'created_term', 'bbloomer_save_wp_editor', 10, 3 );
 
function bbloomer_save_wp_editor( $term_id, $tt_id = '', $taxonomy = '' ) {
   if ( isset( $_POST['seconddesc'] ) && 'product_cat' === $taxonomy ) {
      update_woocommerce_term_meta( $term_id, 'seconddesc', esc_attr( $_POST['seconddesc'] ) );
   }
}
 
// ---------------
// 4. Display field under products @ Product Category pages 
 
add_action( 'woocommerce_after_shop_loop', 'bbloomer_display_wp_editor_content', 5 );
 
function bbloomer_display_wp_editor_content() {
   if ( is_product_taxonomy() ) {
      $term = get_queried_object();
      if ( $term && ! empty( get_woocommerce_term_meta( $term->term_id, 'seconddesc', true ) ) ) {
         echo '<p class="term-description">' . wc_format_content( htmlspecialchars_decode( get_woocommerce_term_meta( $term->term_id, 'seconddesc', true ) ) ) . '</p>';
      }
   }
}