When connecting or pairing one Bluetooth device with another, at least one of the devices will require you to enter a passkey. Some Bluetooth devices have a passkey you can't change, while other Bluetooth devices do not have set passkeys. When you go through the pairing process, the device either generates a random passkey or asks you to create your own passkey.
Try entering "0000" or "1234" as the passkey. Many Bluetooth devices such as headsets and mobile phones use one of these two passwords by default.
Check the manual for your Bluetooth device. The default Bluetooth passkey is always included in the manual. Check the section on Bluetooth or Bluetooth pairing.
Look up the model number of your Bluetooth device on the support section of the manufacturer's website. You can usually find documentation or an FAQ that lists the Bluetooth passkey.
Contact the manufacturer's support number. The number is located on the website or in the manual.