@davilaomg - glad to hear that you were able to make some progress. That was a teaser, $5 to open each actions jk 🙂
Ok, I just tested on my dev tenant and got this working end to end (create to update). Give below a try and let us know if you have any further questions.

Set variable "SPEventId" to
first(outputs('Event_found_update_the_event_in_SP_list')?['body/value'])?['Id']
Note: Follow naming conventions for prod deployment.
Thanks
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