Google ad crashed site

I tried putting in code from Google Ads onto my theme file editor under function.php and it crashed my entire website. Since then, I received “There has been a critical error on your website. Please check your site admin email inbox for instructions.”

I also deleted the current theme and now I am unable to go into Theme File Editor and remove the code I pasted.
Now I get – Error: The theme directory “enterprise-pro” does not exist.

How can I get my website back up and running?

The page I need help with: [log in to see the link]