Not really a solution, but help[
^]
This is the essence of the answer:
Try taking the ORGANIZER line out, in which case the organizer should
default to the person opening the ics file, and they will become the
organizer once they send the request out. I don't know how to get rid
of the "Send update" text on the button. Outlook thinks it's a reply
to an existing request, rather than a new one.
The best way I've found to troubleshoot ics issues is to just try
taking fields out and see what happens.
I have not found a reference
on what the exact effect on each field in Outlook is, if there is such
a thing.
If this helps please take time to accept the solution. Thank you.