Add displayFooter hook in my new theme

[nikoz]

I recently bought a GDRP module that is not being displayed in my theme. I have contacted with the module developer and he told me to contact my theme developer and ask him to fix this or implement the footer hooks, in order for the GDPR popup to be displayed in the footer hooks. My theme is not displaying the core footer hooks. So, I have contacted them and their reply was to fix it on my own if I want this module to be displayed.

So..how do I add a footer hook in my theme ? Is is simple ? I tried to search around for a tutorial but I get a bit confused

I use Prestashop 1.7

Thank you