Looking for alternatives to auth0, Eartho and Firebase auth (user login service)

Need some wisdom here. Looking for alternatives to Auth0 and Eartho.io . Got this basic site running on Hapi.js with good ol' vanilla JS for client stuff, no fancy frameworks

Need to add user logins for some extra features but don't want to deal with all the security headaches of DIY-ing it.

Tried both Auth0 and Firebase Auth, but no luck. Even followed Auth0's guides to the letter, still getting authentication errors with no clear fixes. And the internet's usual helpfulness is MIA.

Probably messing something up, but I'm 4 days behind schedule now. Just want a no-fuss login/user system, no framework baggage. Any suggestions?

Someone has experience with Eartho?