How to use outlook add-in on internal domain

Question

Hi guys.

We are developing outlook add-in based on https://learn.microsoft.com/en-us/office/dev/add-ins/develop/create-sso-office-add-ins-aspnet.

We made it working for localhost, and we need it to be working also on internal domains for testing purposes.

But "Application ID URI" in Azure registration should contain either localhost or verified domain(api://<fully-qualified-domain-name>/<app-id>).

Is there any options to run add-in with internal domain, other than verifying custom domain ?

It is strange that Redirect URI does not have verified domain validation, but Application ID URI has...

Thank you in advance.