I'm trying to update my registered application in Azure to Multi-tenant from Single-tenant and it is throwing me the below error. I tried modifying the Application ID URI under Expose an API section but not able to figure out. Please help.
Unable to update the Supported account type. The property Application ID URI (found under "Expose an API") must be on a tenant verified domain. [kIW6f]
As the error is pointing out, you need to update the Application ID URI for your app registration.
It probably has a value currently which isn't using any verified domain for your tenant. Let's say it's current value is https://example.com/yourapp1 where example.com is not a verified domain yet.
You can try updating the Application ID URI to a value like -
"https://{yourtenant}.onmicrosoft.com/yourapp1"
This should work because {yourtenant}.onmicrosoft.com is already a verified domain for any Azure AD tenant.
In case your Azure AD tenant already has another verified domain like yourcompany.com you could use that as well. e.g. https://yourcompany.com/yourapp123
Here are a couple of simple ways to do this update -
Go to your App registration > Expose an API > Application ID URI (Edit)
Go to your App registration > Manifest > Update the "identifierUris". e.g.
"identifierUris": [
"https://{yourtenant}.onmicrosoft.com/yourapp1"
]
On a side note, Application ID URI value can be any valid URI starting with HTTPS, API, URN, MS-APPX. It must not end in a slash. So if you want to use a different format, you could do that as well.
In fact, even if you have an empty value set for Application ID URI even in that case you will be able to change the authentication type from single tenant to multi-tenant. You're seeing an error only because of an invalid value being there currently.
