passwordless User Authentication token for integration testing

We are doing integration testing for our application, and i faced the following issue:

We do require the users to login passwordlessly through sms, for the app to go forward with its flow we use the auth token of the user and get the user auth_id from it afterwards.

The problem is that for integration testing, it is not convenient for us to send it over an sms and type in the sms code to continue, is there a way to log in the user using sms but without the verification code? our tests run on the server, and we can use non-interactive clients if that helps.

You do recommend the usage of a browser to login regardless of the criteria, as you have redirect urls per each login (others are deprecated) what if i want to login from a server rather than a browser? how do we solve this issue without having an http server listening for a post request?