Thanks for the reply
The theme I used is WP Store of 8Degree Themes.
I tried to write to the producer of the theme but they did not answer me.
I tried to follow the guide you suggested and editing the file function.php of the theme and adding lines to manage the size of the images I managed to change the thumbnails of the categories but the main image of the product page I can not change it , it always remains with a width of 558px.
Can I do something else?
