For Android Wear OS 2 and 3: you need to install Golf Pad on your phone and smart watch. Open Play Store on the watch and choose Golf Pad from the tab named "Apps on your phone".
Or install it via Play Store on your phone. Go to Galaxy Wearable app > Store and find Golf Pad. Then, install Golf Pad under "Available on more devices":
Then enable the smart watch link in Golf Pad preferences on your phone. Make sure that the watch is connected to your phone over bluetooth. The first time you use the Wear watch with Golf Pad there may be a delay to the distances showing up on the watch. Do not be alarmed, this only happens the first time you use it, after that the distance and score updates will be instant.
If you use a GPS-equipped smartwatch, you can use it in Standalone mode. See more info here: Can I use my GPS-equipped Wear OS watch without a phone (in Standalone mode)?
Note: Android Wear 1.X is not supported because Google terminated support for Wear OS 1.5 and older versions in 2020.
For more information and troubleshooting please check this page.