MTS 81231FT Unlock from the operator SIM decoupling

Router MTS 81231FT how to unlock from the MTS operator?
What to do if the MTS 81231FT modem asks for a code with SIM cards from another operator?
Where can I get the unlock code for the 81231FT modem?
How to officially untie the router from the operator?
Unlocking the MTS 81231FT router using the NCK code is a safe and discreet way to unlock the router. Removing the Sim-Lock lock using a code does not void your warranty, because the manufacturer of this device has provided exactly this type of unlock.