How do I format a date that was returned from a previous action

I'm experimenting with Power Automate. I have the action 'Find meeting times' to find me the meeting times for two calendars.
I'd like to take the first option and create an event with it.
So this is how my flow looks like now:

This returns an error:

OpenApiOperationParameterTypeConversionFailed. The 'inputs.parameters' of workflow operation 'Create_event_(V4)_2' of type 'OpenApiConnection' is not valid. 
Error details: Input parameter 'item/start' is required to be of type 'String/date-no-tz'. 
The source type/format 'Object' of the value '{"confidence":100.0,"organizerAvailability":"free","attendeeAvailability":[{"availability":"free","attendee":{"emailAddress":{"address":"name@email.com"}}}],"locations":[],"meetingTimeSlot":{"start":{"dateTime":"2023-05-26T10:00:00.0000000","timeZone":"UTC"},"end":{"dateTime":"2023-05-26T10:30:00.0000000","timeZone":"UTC"}}}' 
is not convertible to type/format 'String/date-no-tz'.

I assume that it takes the whole JSON body, instead of just the 'start' datetime.

What would be the correct way to solve this issue?
I've tried to navigate around the JSON object, but I'm stumped at the first node, that doesn't have a name:

My attempts look like this: first(outputs('Find_meeting_times_(V2)')?['body/meetingTimeSuggestions']?['parameters']?['item/end']?['meetingtimeslot']?['end']?['datetime'])

The expression for the start time of the first option would be:

first(outputs('Find_meeting_times_(V2)')?['body/meetingTimeSuggestions'])['meetingTimeSlot']['start']['dateTime']

The end time would be:

first(outputs('Find_meeting_times_(V2)')?['body/meetingTimeSuggestions'])['meetingTimeSlot']['end']['dateTime']