Bir siteden bunları buldum.
Kaynak site: https://forum.opencart.com/viewtopic.php?t=101403

Orijinal versiyonu indirin language klasörünü kendi sitene upload et diyor sonra ayarlara aşağıdakileri ekle diyor

download the original version of OpenCart, and upload back the language folder. It will merge in all the english files.

Then, go to system > localisation > language and add the following

language name: English
code: en
Locale: en_US.UTF-8,en_US,en-gb,english
Image: gb.png
directory: english
filename: english
status: enabled