This is a question about manipulating a calendar list item in a modern site in SharePoint Online.
When I open a calendar item, there are three tabs in my ribbon: Browse, View and Custom Commands.
I would like to add another item to Custom Commands. Something to run a piece of code. How can I do this? I assume SPFx is out of the question, since a calendar isn't a modern list.
Background: I'm building a course schedule and want the user to be able to register for the course when viewing the list item.
Thankful for any help and ideas.