How to activate and use Sim Toolkit on A6 GSM Module

Question

I am having trouble with A6 GSM module. I need to activate and use sim toolkit but when I try at commands I am getting CME ERROR 58. (I can make calls, send sms and use ussd with at commands, there is no problem with the connection.)

Some of the commands that I try and get the Error 58:

AT+STSF=1
AT+STSF=?
AT+STGR=1
AT*PSSTKI=1
AT*PSSTK="SETUP MENU",1,1

I am getting CME ERROR 255 when I type these:

AT^STGI=16

Could you please help me? What should I do to activate and use Sim Toolkit?

Thank you, Best regards