I'm using a theme with testimonial slider in homepage and I've figured out that there in the module folder a file called all_testimonial.tpl and something about an upload form.
So I guess that there is a way to have a page with all testimonials with the upload form.
But I'm not able to understand how could use that tpl.
Do you have any suggestions?
TPL file is a file extension for a template file format in general.
In Prestashop, Smarty is a template parser written in PHP
Take a have a look at these websites
It would be difficult to answer which module for testimonial slider you are using in theme and which PrestaShop version website is using.
But I would say to have a look at the Prestashop Hooks
To see List of Hooks -> For a full list of Hooks
To see Module Development Changes -> https://build.prestashop.com/news/module-development-changes-in-17/