Power Automate formatDateTime() is a useful expression that I use when i need to log flow actions, but I often forget the syntax, so this is a log for it.
To play around with this expression
Create a new manually trigger flow, name it was you will
Create two data compose actions, the first one just output the date time utcNow() as example.

The second compose actions will use the expression, formatDateTime(utcNow(),’dd.MM.yyyy HH:mm’)
Save and run your flow, the output should be as below
