Hi.
This is only product.tpl. As I wrote, product-details.tpl also needs to be modified.
Can you please tell me which version of Prestashop you are using and if you are using the classic theme?
I am also sending edited files from PS 8.1.3.
product.tpl (on the left is the original, on the right modified):
product-details.tpl (on the left is the original, on the right modified):
result: