Hi @mahdi1,
If you are trying to get tokens for test users, you can check out the Resource Owner Password Flow, which allows you to exchange a username/password directly for a token, bypassing the login prompt.
If you are trying to retrieve tokens for your real users, this is not going to be as simple. Auth0 doesn’t provide any sort of impersonation that would let you get a token for a user without having access to their password.
Hope this helps!