Font won't change in my theme

[mars12]

I currently use the Prestige theme and want to change my font, but had hired a third party developer to get the site set up. They had used a font license which recently expired and so now my website is defaulted to a font that I don't like. How do I remove the current coding on my site so I can start using the fonts provided by my theme? 

[mars12]

Just want to change the font to "inter" and store url is https://www.tenetshop.com/

thank you!

[mars12]

Thank you for your reply. My theme offers the font Inter and when I try to change it to this, it won't apply so I don't think I need to neccesarily add it into my code.