Carrier app throws SecurityException when adding an APN

Question

We have an eUICC with carrier privileges, we are able to check the privileges by

telephonyManager.hasCarrierPrivileges() and it returns true.

Android documentation says that we are able to use the Content provider APIs to add, modify an APN.

But we are still unable to add the APNs. the stack trace

java.lang.SecurityException: No permission to access APN settings
        at com.android.providers.telephony.TelephonyProvider.checkPermission(TelephonyProvider.java:7029)
        at com.android.providers.telephony.TelephonyProvider.insertSingleRow(TelephonyProvider.java:5948) ```