The One-Time-Password (OTP) is a temporary code generated by Fido and sent to your phone via SMS. It is used to verify your mobile number. You will receive a new OTP each time you log in to your Fido account.
Your PIN, on the other hand, is a 4-digit security code that you set up yourself. Only you will know this PIN. You’ll need both the OTP and your PIN each time you log in to your Fido account.