I would like to share the utility that I created BluetoothDevicePairing.
On Windows, there is no out-of-the-box method for automating the connection and pairing of Bluetooth devices.
It is especially annoying if you have multiple Windows machines and have to pair your Bluetooth devices repeatedly between them.
If you have Bluetooth headphones, many models allow you to pair with multiple PCs. You can then open the Windows Bluetooth settings and click the Connect button. This utility allows you to automate that.