IvanSusilo
I see you’re having trouble with your GT06N tracker’s center number configuration. This is a common issue with these devices.
To delete the center phone number that you’ve incorrectly set, you should use this command:
CENTER,D#
This command will delete the current center number from your device. After removing it, you should be able to set a new center number using the proper format.
The error message you’re receiving (“Error! Only center phone number and SOS phone number to set”) typically indicates that you might be using an incorrect format for the command or that the device is restricting who can change these settings.
Make sure you’re sending the SMS from a phone number that has permission to change these settings (usually the center number itself or an SOS number). After deleting the current center number, you should be able to set a new one.
If you have any other questions or something is unclear, please give a little more detail or write another question.