Allow authenticated but anonymous responses with one response per person

The inability to create forms to external guests is a massive failure.

I want to receive data for service requests from my clients, but the only way to allow that through this system is to give them all a seat on our Microsoft package. 

Google Forms allows you to record anything, if the user consents to give data that is their right, does Microsoft have their own version of GDPR or something? Com-eon Microsoft I'm not impressed.

What's the point of having such an intricate system which returns every external person as anonymous. Useless. How am I supposed to know who submitted the request? I need to authorize the request via encryption to make sure sure the requester is valid.

SORT THIS OUT