How to register my app for openURL()

In the following app, all Buttons open the expected app except the 1st one for “MyApp”. MyApp is installed on the iPhone, but I don’t know what I need to do in order for it to behave similarly to Apple’s Maps & Music, and Uber…

struct ContentView: View {
	@Environment(\.openURL) var openURL

	var body: some View {
		Button("Launch MyApp") 	{	openURL(URL(string:"MyApp://")!)  }
		Button("Launch Maps") 	{	openURL(URL(string:"Maps://")!)  }
		Button("Launch Music") 	{	openURL(URL(string:"Music://")!)  }
		Button("Launch Uber") 	{	openURL(URL(string:"Uber://")!)  }
	}	
}