How to add new column in opencart product admin?

Question

opencart

admin panel - catalog - products
I want to display a column where the date of adding the product will be shown,
I understand that I need to change /admin/controller/catalog/product_list.tpl I
made a copy of an existing column for the test, but some garbage came out ...

or I'm crooked I changed something in the product_list.tpl file, or do I need to edit something else

Answer 1

You probably didn't correctly add the product_list.tpl skinte file to the column