Hi @Anonymous ,
Do you want to only show Time value from the Date Time type field in your SP list?
Based on the needs that you mentioned, I think the Text function could achieve your needs. I have made a test on my side, please try the following formula:

Set the Text property of a Label to following:
Text(Now(), "HH:mm AM/PM")
If you list your SP List records in a Gallery, and you want to display the Time value from the Date time field in this Gallery, add a Label in this Gallery, set the Text property to following:
Text(ThisItem.DateTimeField, "HH:mm AM/PM")
More details about Text function, please check the following article:
Text function
Best regards,