Question: Please help regarding Coding Multi-lingual site

I have a question: I have a site in French and English. Everything is done and translated and it works great. However I wanted to know if we could customize the source code in Wix so that my french pages show to google that they are French pages. Currently all my pages are showing in the source code as English. I would like for Google to be able to tell the difference with this content so that it doesnt think it’s duplicate content. Is there a way to cutomize the programming of the each page’s language. I do not want to have multiple domain names for fr or en. Just wondering if a programmer can customize this?
Thank you.

Yvan