I want to implement authentication using azure ad b2c. I have covered all the prior requirements such as an azure b2c tenant account(directory) and have an idea of registering application.

My main requirement is to just have sign in policy and no sign up policy. To do so I need to create users, right?(to provide login creds to users with password reset on first sign in.) I have an idea that it could be done through graph but please provide some information for it as well.

Please provide any prior implementation reference of the above requirement if you have.