Hi @Danny Sanchez , you can do this by using B2C and following this guide.
- Sign in to the Azure portal.
- Make sure you're using the directory that contains your Azure AD B2C tenant. Select the Directories + subscriptions icon in the portal toolbar.
- On the Portal settings | Directories + subscriptions page, find your Azure AD B2C directory in the Directory name list, and then select Switch.
- In the left menu, select Azure AD B2C. Or, select All services and search for and select Azure AD B2C.
- Choose All services in the top-left corner of the Azure portal, search for and select Azure AD B2C.
- Select User attributes, and then select Add.
- Provide a Name for the custom attribute (for example, "Birthday").
- Choose a Data Type. Only String, Boolean, and Int are available.
- Optionally, enter a Description for informational purposes.
- Select Create.
Please let me know if you have any questions and I can help you further.
If this answer helps you please mark "Accept Answer" so other users can reference it.
Thank you,
James