It probably isn’t connecting because you didn’t accept the RSA key first time.
Go to Settings -> Gear info -> About device.
Tap on Software version 5 times. Then a confirmation pop up displayed once the Developer options is enabled. (OPR checking only at this time)
Make sure Debugging is on in About Watch settings
Hold down the home key until rebooting appears.
Connect your phone to your computer.
Allow Data Access
On the phone make sure USB debugging is enabled in the Developer Options
From the \program files\Galaxy Watch Designer\Tizen\Tools
copy sdboverbt_160523.apk to your phone and install it.
In older versions of Windows you may need the Android USB Drive for Windows on your PC you can get it here. https://developer.samsung.com/galaxy/others/android-usb-driver-for-windows
Make sure debugging is enable for both your watch and phone
On the phone enable USB debugging in the developer Options
Launch SDBoverBT on your phone
It will ask you to select your device it will show your watch click on it and it will be connected
You will have to agree to the RSA encryption or some other permission the first time and it doesn’t show very long so be sure you have your watch handy and running when you do that.
Once you are connected plug your phone into your computer and allow data transfer on your phone
launch GWD and from your project chose run on device
It will start the scan and then it will show the SDBoverBT icon