I'm going to start with I have looked at templates, attempted to do this with an Excel table as the tracker, and have tried multiple combinations of Flow actions/conditions. At this point I'm convinced this cannot be done without PowerApps, but thought I'd reach out for assistance.
We have a Microsoft Form for staff to register for training on a specific date that they choose from a list of 5 dates. Here's what we'd LIKE to have happen:
1. When a Form response is submitted, track the number of attendees for each date.
2. When each date reaches capacity (lets say 5 for this discussion), future responses/registrations are declined.
3. When a registration is submitted for an available date, the user receives a calendar invite and separate email confirmation.
4. When a registration is submitted for an unavailable date (reached it's capacity), the user receives an email saying registration declined.
So far I've been able to create the Form, track the attendees on an Excel table, create a second table with COUNTIF formulas for each date, and I THOUGHT I had the conditions for sending the messages. However, it doesn't work as intended because I can't figure out how to tie the row (date) to the column (registrants) so that it only sends one email. In testing, it sent 8 emails to the registrant, one for each date, regardless of which one they registered for.


Any suggestions, even if it's to say this cannot be done without PowerApps, would be super helpful! Thanks