I'd say it's not possible in pure HTML + JS (as in, encryption/ access control performed entirely there). The solution (with a server) is: https://oauth2-proxy

I'd say it's not possible in pure HTML + JS (as in, encryption/ access control performed entirely there). The solution (with a server) is: https://oauth2-proxy.github.io/oauth2-proxy/ https://oauth2-proxy.github.io/oauth2-proxy/