I have a Bluetooth device and I do not remember the pairing code (aka passcode, passkey, PIN)
This device is already paired on an Android device but I don’t know how to recover the pairing code.
Do not recommend me to search to check producer documentation or online, in this case it doesn’t work.
In the vast majority of devices with PINs they are set to 0000 or 1234. Other than that you would have to learn it from the manufacturer. Your android device will not have the saved PIN anywhere because PIN is used only temporarily during pairing procedure, then other outputs (keys) are saved for future connections.