HI, This is more of a doubt since I could not finding anything related to this in your documentation.

[sonuoommen]

In devise it is configurable to use email or mobile_number or username as we wish with password for authentication or sign in.
Is it possible with this gem ?. Can I use mobile_numer instead of email ?
I am getting this error "undefined method `provider' for #<User:" which I can see from code is hardcoded to be email.

[booleanbetrayal]

provider refers to the mechanism used to distinguish the user (email, facebook, github, etc), where uid is the globally unique value for that provider. In theory, you could add support for any provider you'd like, but this is not a particular provider option that devise_token_auth supports out of the box. Hope this helps!