When I type the command in adb:
./adb shell am start -W -a android.intent.action.VIEW -d \"example:gizmos\" com.myapp
I get this error:
Try this:
adb shell am start -a android.intent.action.VIEW -c android.intent.category.BROWSABLE -d 'yourdeeplink'
-a android.intent.action.VIEW -> action -c android.intent.category.BROWSABLE -> category -d 'deeplink' -> data
and also you need to install the app first in order to register the deeplink.