I don't see Azure AD authentication using app registration is available for pgadmin4. I see other authentication mechanisms via LDAP, OAUTH2 and kerberos.
Could you let me know if there is a possibility of enabling it?
We don't support Azure AD auth, and currently have no plans to add it. You're welcome to add a feature request at https://redmine.postgresql.org/projects/pgadmin4/issues, but it's unlikely any of the regular developers will work on it in the near future.