How to create a registration form with max participants per session

I'm creating a registration form for a company event. Our staff member need to select which session they would like to follow. Every session has a maximum amount of participants.

I would like, when a session limit is reached, for the session (option) in the dropdown to show that the session is full or that a text field apears which says the chosen session is full.

Is this possible?
Kind regards.

Hello @Go2900,

Welcome to the Plumsail Community!

Yes, it is possible. You can store the list of the sessions with the count of participants in the Excel files stored in OneDrive. You can use this file as a source to populate Drop Down field on the form. Find more information here.

And you need to set up a Microsoft Flow that will update the Excel file. Thus, after the user selects a session and submits the form, the number of participants is updated by the thread. When the number of participants reaches the maximum, the thread will add a 'Full' note to the session name.