There are several steps taken by both the Customer and Kapiche to get Azure AD/Entra set up:
Customer needs to register the Kapiche App - see here for instructions: https://learn.microsoft.com/en-us/entra/identity-platform/quickstart-register-app
The redirect URL required during registration is https://auth.kapiche.com/login/callback
Don't forget to Grant Admin Consent -> https://learn.microsoft.com/en-us/entra/identity-platform/quickstart-register-app#grant-admin-consent-external-tenants-only
Customer then supplies Kapiche:
Azure domain
Client ID / Application (client) ID
Client secret value (Not the Client Secret ID)
Kapiche will setup Azure AD on the Customer's Kapiche site.
Kapiche or Kapiche Customer Admins can then send invite links to nominated Customer Users and the Customer User/s registers via Azure Ad.
This means the Customer Users will go to login via their company Azure AD and get redirected back to Kapiche.
The Customer User will then need to setup 2FA.