Nissan Micra K12 Radio Code Help

The radio is locked after switching the battery. After 3 false attempts it showed me the serial and the device number:

Serial Number : 3126363
Device Number : 7612830023

Can you help me find the radio code ? Or do i need the other serial number that i have to remove the radio to see ?
I may be stating the obvious but after I changed the battery I had to reset the radio
I had the correct 4 digit code but when I installed it it didn’t work and messaged “wait 1 hour”
I locked the car and came back after about 2 hours
Tried again and this time couldn’t even input the 4 digits
This went on for a while until I realised you have to wait 1 hour with the radio switched on
This is difficult where I live because it means the car is unlocked with the ignition on parked in the street for an hour (difficult to explain on an insurance claim form)
Anyway when I tried again the display read “0000” and I was able to input the code and the radio/CD worked