Entra, External Id, Authentication, Mobile App Development.
https://tenant.ciamlogin.com/tenant.onmicrosoft.com/oauth2/v2.0/initiate and the form parameters are: client_id=11...11 &challenge_type=password redirect &username=nativeauth@company.co.nz where the username is the name of the person who is logging in. The response will be: { "continuation_token":