Apple Watch fall detection without 911

It doesn't work that way.

Use Fall Detection with Apple Watch - Apple Support

M1 Mac mini, macOS 13.5.2;  Watch, series 7 GPS/cellular, watchOS 9.6.2; iPad Pro 2nd Gen, iPadOS 16.6.1; iPhone 12 Pro, iOS 16.6.1; TV 4th Gen, tvOS 16.6; HomePods, audioOS 16.5 and Airport Express w/ Airplay 2

I don’t believe this is possible. I think it’s built into the software to call 911 and notify your Emergency Contacts. I am pretty sure that there isn’t a way to turn off the Emergency Services calling without turning off the detection alltogether.