This is an automatic service code after the payment get to the specified email.
Ordering unlock code for your phone MTS 975, MTS and Megafon Optima 982
Phone IMEI and provider ID that looks like this (978X-2DMSRU1), all this is under the battery box or on the phone. You can still see the IMEI by typing * # 06 #
When installed in a mobile phone SIM card will be someone else´s code request, and to enter a code. Not to be confused with a PIN code that SIM card.
The code is entered once and for all, more requests when a new SIM card will not.