Azure AD B2C Password reset does not work when the users are created using the graph API and Sign In Name as Username

I am using Azure AD B2C with Username login for my application. I am creating,updating and deleting users using the graph API and there is no way of adding a primary email programatically (I can only add the "OtherMail" property in the graph api) so as to later use it in the password reset policy for verification. So now I have no way of resetting the password using my password reset policy.

Please suggest me a solution to this problem.