Hi @I. BACHAR
Thank you for posting this in Microsoft Q&A.
OTP (one-time passcode) will work on below scenarios.
- The inviting tenant didn't set up federation with social (like Google) or other identity providers.
- Email one-time passcode is enabled.
- If user don't have a Microsoft Entra account.
- They don't have a Microsoft account.
- They don't have any other authentication method or any password-backed accounts.
Based on the information you provided, it seems that you have set up One Time Passcode in your tenant. Can you please check remaining scenarios?
For your reference: When does a guest user get a one-time passcode
The redemption process verifies whether the user possesses a home directory or not. In the event that the user's home directory is recognized, the user is directed to the relevant identity provider for authentication. If no home directory is detected and the email one-time passcode functionality is activated for guests, a passcode is dispatched to the user via the provided email address.
Thanks,
Navya.
Hope this helps. Do let us know if you any further queries.