Create a Microsoft Form for registration.
Create a new Power Automate flow.
In the trigger, select "Microsoft Forms" as the trigger and choose the form you created in step 1.
Add an "Initialize variable" action to create a variable for the email address of the attendee. You can extract the email address from the form response data.
Add an "Outlook" action, choose the "Create Event" action and provide the necessary details for the calendar event, such as the subject, start time, end time, location, etc. You can also use the email address variable from the previous step as the attendee email.
Add a "Send email" action and select the "Outlook" connector. In the "To" field, use the email address variable, and in the body of the email, include the details of the event such as the date, time, and location.
Save and test your flow.
Now, whenever a new registration is submitted using the Microsoft Form, a calendar invite and email notification will be sent to the attendee.