Thank you for the information. Please proceed in downloading, and installing your Bluetooth drivers in this link.
https://ftp.hp.com/pub/softpaq/sp112001-112500/...
Then, please restart your computer after the installation.
After the restart, Ensure the headphones are powered off. If they are connected to a charging cable, unplug it. Press and hold both the power button and the volume down (–) button simultaneously for about 10 seconds. The blue indicator light will flash four times, indicating that the headphones have been reset to factory settings.
After resetting, turn on the headphones. They will automatically enter pairing mode, indicated by the blue indicator flashing twice repeatedly and a voice prompt saying, "Pairing." If they don't enter pairing mode automatically, press and hold the Bluetooth button for about 5 seconds until the blue indicator starts flashing.
On your laptop, click the Start button and select Settings. Navigate to Bluetooth & devices and ensure Bluetooth is turned on. Click Add device, then choose Bluetooth from the options. Select WH-CH520 from the list of available devices. If prompted for a passkey, enter "0000."
Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install.