If you have a common bank account linked with Cash app and PayPal, you may withdraw to bank account from Cash app and then add funds to PayPal from linked bank account. Can't add funds with a card at PayPal, card use is primarily for purchases or sending money. That is the ONLY way. To transfer funds from PayPal to Cash app do the reverse, withdraw from PayPal to bank account or non-paypal branded debit card for 1% fee and then add cash to your cash app via bank account or the non-paypal branded debit card.