Custom URL for Azure AD B2C signup and signin pages

Question

I'm working on integrating Azure Active directory B2C for sign-up and sign-in process. By default, when a user clicks the login button, it has to redirect the user to a different domain ( microsoftonline.com ) such that the URL for sign-up and sign-in page is in the following format:

https://login.microsoftonline.com/te/tenant-name.onmicrosoft.com/b2c_1_signupsignin1/oauth2/v2.0/authorize .......

However, I think this is a bad user experience for users redirecting them to other domain for signing in. So I'd like to use my own domain (eg example.com) so that the URL should be like below.

https://login.example.com/te/tenant-name.onmicrosoft.com/b2c_1_signupsignin1/oauth2/v2.0/authorize .......

I've done some research on Azure documentation and found out that it does not currently support setting up the custom URL for sign-up and sign-in page.
https://docs.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-faqs

However, the case study from Azure B2C mentioned that the Real Madrid offical home page also uses Azure AD B2C for user management ( https://customers.microsoft.com/en-ca/story/real-madrid ). However, the domain in the URL for sign-in page is not microsoftonline.com but their own domain, realmadrid.com , like below

https://pro.login.realmadrid.com/rmglndpdaadfans.onmicrosoft.com/oauth2/authorize?p=B2C_1_SignInSignUpWeb&client_id=8a943960-87f9-4e22-bc2a-40099d584719&redirect_uri=http%3A%2F%2Fwww.realmadrid.com%2Fcs%2FSatellite%3Fpagename%3DRealMadridResponsive%2FPage%2FRM_IDPRespuesta&resource=https%3A%2F%2Frmglndpdaadfans.onmicrosoft.com%2Fwebapi&response_mode=fragment&response_type=token+id_token&scope=openid&nonce=defaultNonce&idpmode=0&lang=en&_ga=2.211460117.1443111640.1554916216-543571806.1554916216

I've checked the following pages but none of them helped..

1. https://techcommunity.microsoft.com/t5/Azure-Active-Directory/B2C-with-custom-login-URL/td-p/44040

2. https://docs.microsoft.com/en-us/azure/active-directory-b2c/active-directory-b2c-faqs

So how can I achieve this as Real Madrid home page did with Azure AD B2C?

Answer 1

Currently, you are able to use the your-tenant-name.b2clogin.com domain (recommended) or the login.microsoftonline.com domain, latter of which is being deprecated.

Work for support of customer-owned domains has been started.

Answer 2

公共预览版现已提供为 B2C 租户使用自定义域的功能https://docs.microsoft.com/en-us/azure/active-directory-b2c/custom-domain?pivots=b2c-user-flow