How to store the result of the at + ccid command to a variable.

Hello everyone.
I'm on a project using arduino nano and sim800l.
In this project I want to validate the sim card number, to prevent them from changing the sim card for another.
My problem is that I can not store the result of the AT + CCID command to a variable.

I am using Serial.writer and mySerial.write. I can not find the result that I want.
I look forward to your kind and grateful help.