@maximiliano-riffo , welcome to the FusionAuth community!
I don't understand what you are trying to do. Are you trying to verify a user's email without sending them an email? I'm not sure I understand how that would work.
If you want to build your own verification system, you can do that.
Create an attribute user.data.verifiedBySMS on user creation and set it to false. Send the user an SMS using any SMS provider. Include the code and a link to a page in your app. When the user enters the code in the app, update user.data.verifiedBySMS to true. Build your application UI to test the value of user.data.verifiedBySMS. You could also put it in a JWT.Maybe I misunderstand your question, though.