go to Play Store and download the Package names app, open it and you will see the apps that are installed on your phone.
or
Try running simple adb commands
adb connect 192.168.xxx.xxx:5555 (your watch IP address & enable debugging)
adb shell
pm list packages
You will get an output list like this
package:com.android.cts.priv.ctsshim
package:com.google.android.ext.services
package:com.android.providers.telephony
The app ID is the text after package:
com.samsung.android.wear.shealth/com.samsung.android.wear.shealth.app.heartrate.view.HeartRateActivity
You should be able to create a new thread in the Watch Face Studio forum home. If you aren’t able to let me know.
Ron
Samsung Developer Relations