Static frontend + Strapi

please help i have exact same question but still its too difficult to understand exact process
i have plesk server for hosting its my company server which i have to use it for i have access to a subdomain where i have to host my app i have added
frontend build files in - front end folder
strapi files in - backend folder (which contain all files including build of strapi )
to run this app i have no idea what is the correct way
like i can run this by creating server.js file and node application and adding http-proxy-middleware pkg init but getting error from strapi (frontend running perfectly )
also found that proxy work on nginx but 0 idea how to set up what the name should give
like i got this /etc/nginx/sites-available/example.com but where do i create ? like at very root level where all website relays or at my project folder where i have frontend and backend folder
Thank in Advance for you valuable help