Hi,
Can you tell me the brand and model of the earphones you're trying to connect? Also, were you able to pair them with another device without any issues?
Most Bluetooth earphones have an indicator light that shows when they're ready to pair. Do you see a blinking blue light on the earphones? If not, try turning off Bluetooth on any devices they were previously connected to, as they may be reconnecting automatically. You may also want to check the user manual for the correct steps to put them into pairing mode.
Once the earphones are in pairing mode and the blue light is blinking, go to Windows Settings > Bluetooth & devices > Add device > Bluetooth and see if they appear in the list of available devices.