You could get this task detail after you update the task. Then put the user id into the Get user action of Azure AD connector, put the Dynamic content into the email field to send the attendee a notification email.
Community Support Team _ Lin Tu
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I also have the same problem with Update Calendar Events.
I am unsure how this invites a new user to the event without sending out repeat invents to currently subscribed users.
I was facing this same problem. Since there is no proper solution, my workaround was to instead forward the invite to the event by doing the following:
1) Schedule the event manually and invite only myself
2) Create a utility flow to search and find the email message ID of the email that triggered when i scheduled the calendar event in step 1
3) In my actual flow, used the 'forward an email (V2)' and used the message ID of the email that i captured in step 2
There are some downsides, notably:
1) The event is received by the recipient as a forwarded invite rather than a proper invitee. This was acceptable for my use case, however
2) If the event is updated manually, you will need to start the process over. This is because the original forwarded invite will be out of date, but will continue to be the one forwarded to new recipients unless a new email is generated.