I'm not a coder, but and Power Automate is just GUI enough for me to get myself in trouble. I've got a flow, hacked from a template that is working for me except for the dang date and time format. The flow grabs an Outlook365 calendar and posts a list of the day's events to a slack channel. But unless people Speak UTC, it ain't pretty. How on earth do I get it to look like "9:00am"?
Here are some expressions I've tried:
formatDateTime(triggerBody()?['Start'],'o'),11,5
formatDateTime('03/15/2018 12:00:00', 'yyyy-MM-ddTHH:mm:ss')
substring(formatDateTime(triggerBody()?['Start'],'o'),11,5)
formatDateTime(convertTimeZone(triggerBody()?['Start'],'GMT Standard Time',triggerBody()?['StartTimeZone']),'yyyy-MM-dd hh:mm')
but all end up throwing an error like this:

Here's my flow in a nutshell:

So I'm suuuure it's something simple, but I've done searching. Any help would be rewarded with a thank you.
-joe