I was able to solve my problem. I didn't use a flow but would be the same thought but could use the same process to grab the calendar ID to pass along to the flow. The advantage of using the Office365 Outlook Connector, is I can grab the event id to be saved and used later.
//Finds the Group Emails
Set(findmyID2,
LookUp(Office365Outlook.CalendarGetTablesV2().value,name="MFR_G2",id));
//Grabs the ID of the calendar based on the persons profile
If(IsBlank(varReviewItem.CalendarID), //Looks to see if the Event is already in Outlook
Set(calitemid, // Used to Grab the Event ID. It changes each time it updates
Office365Outlook.V4CalendarPostItem(findmyID2, //Calendar ID
SubjectInput.Text,
DateTimeValue(Text(DateLeaving.SelectedDate,"yyyy-mm-dd")&"T19:00:00"),
DateTimeValue(Text(DateReturning.SelectedDate,"yyyy-mm-dd")&"T19:00:00"),
"UTC",
{body:BodyInput.Text,
location:LocationCalInput.Text,
isAllDay:true}).id),
//Updates the Event
Set(calitemid,
Office365Outlook.V4CalendarPatchItem(findmyID2,varReviewItem.CalendarID, //Calendar ID, Event ID
SubjectInput.Text,
DateTimeValue(Text(DateLeaving.SelectedDate,"yyyy-mm-dd")&"T19:00:00"),
DateTimeValue(Text(DateReturning.SelectedDate,"yyyy-mm-dd")&"T19:00:00"),
"UTC",
{body:BodyInput.Text,
location:LocationCalInput.Text,
isAllDay:true}
).id)
);