Hey, @mortada03 !
Thanks for the response.
While I am not able to locate this on our Theme Store, it looks like the Booster Theme team has a Help Center with some resources about the theme. I found an article called Most popular Booster in-theme apps that outlines that this theme has a few built in apps that provide functionality like upselling and crosselling. So it’s very possible that the discount pop up you are seeing can be turned off within your theme editor.
My suggestion here would be to reach out through their contact page and ask if they can point you in the right direction.
Kindly reply back to this thread with any questions or updates. Thanks!