For Rails API-only authentication, do you go for a gem or 3D party service?

[reinvanim]

I am looking for an authentication solution for a mobile app/Rails backend and there seem to be so many options that I'm a bit lost.

Obviously, I don't want to build authentication myself but I'm not sure if something like Devise is a better solution than something like Firebase.

I like that Firebase offers cheap SMS authentication, while I like that Devise is just a gem I can implement.

Any experience in this field would be greatly welcomed!

Cheers and have a great weekend!