Thank you for posting this in Microsoft Q&A.
I understand that you are looking for a way to provide a direct link to the sign-up form in Entra External ID without first going through the sign-in view and clicking the "No account? Create one" link.
Unfortunately, there is no direct link to the sign-up form from a web app with Entra External ID. The URL endpoint for your user flow to redirect users directly to the sign-in view with the prompt=login
parameter. This parameter forces the user to enter their credentials on that request, so there is no direct option to land on the sign-up page.
Here's an example of what the URL endpoint might look like:
https://<tenant>.ciamlogin.com/<tenant>.onmicrosoft.com/oauth2/v2.0/authorize?client_id=af18cd68-e598-484e-a706-1234567&nonce=ClyDjki&redirect_uri=https://jwt.ms&scope=openid&response_type=id_token&prompt=login
I hope this helps! Let me know if you have any other questions.
Thanks,
Navya