Restrict access to a Form to include external users in our tenant?

Hello,

I'm setting up an automation where a Form response triggers a Power Automate Flow that updates a non-critical value in Business Central records.

It works well except that I want the form to be non-public but to still be usable for people that are from different tenants but added as guests or members in our Entra.

I haven't found what kind of setup and changes I need to make for this to be possible, I feel like it's either people within my domain or public, nothing in between. Is there really no way to restrict access to exclude public and anonymous users but include users from externa tenants and invited in my domain ?

This is the current Entra setup for the kind of user I want to be able to access the form, I have tried with both user type Guest and Member but no change.

Thank you