You can generate 3 additional sets of keys (public and private): gold, silver and bronze. In addition, you can generate a separate set for the Surf Security Card.
To add three additional sets of multisignature keys to Surf:
At the top of the home screen, tap the nut icon.
In the Settings, select Signatures.
Click + and select Derive 3 pairs of keys.
Confirm the action with a PIN code, by scanning your fingerprint or using facial recognition.