Hi! Sorry to hear you’re having trouble pairing the device. Please confirm the headset is in pairing mode. Also, test whether another device (like a phone) can detect the headphones, and whether your PC can detect other Bluetooth devices, this quickly tells us if the issue is on the headset side or the PC side.
If the PC is the issue, go to Settings > Bluetooth & devices, Remove device for the headphones, toggle Bluetooth Off/On, then try Add device again, and when pairing, select the device name without any “LE-” prefix if you see both.