How to acknowledge fall alert on Apple Watch 5.

When I trip the fall alert, is there any special way to tap, stroke or whatever to say, "I'm OK"?

I tap, tap harder, stroke, hold the tap and anything else I can think of but the alert will not go away. Then when it finally does I don't know whether it has timed out or if I have finally gotten the right touch.

Can someone tell me the proper way to cancel an alert and tell me if the watch is supposed to show my action?