Is there, or will there be, an action to create a calendar event from Drafts (iOS) for Outlook Calendar?
If Outlook is synced to a calendar you have defined in the iOS calendars (e.g. An Exchange calendar also available in the Calendar app), then the standard Event action step will do this.
There is a predefined action of just this step in the action directory.
I was looking for a solution directly to the Outlook app for iPhone; I’d rather keep all my email accounts/events in the Outlook app instead of bouncing back and forth in iOS native email and calendar.
I’m not aware of any way the Outlook app supports creating events via URL/etc. that could be integrated with Drafts. They may exist, but I haven’t seen examples or documentation.
That said, if you have created your Exchange account in iOS settings, you can use the system tools through Drafts to create events and they will appear in your Outlook app calendar. There’s no need to use the built-in apps, just have the accounts available so the calendars can sync.