You clearly do not have the system wired up correctly. If you don't understand how to properly connect a telephone line to a security panel, then pay an alarm installer to do it for you.
Aside from that, you should know that, if you try to use an OBiTALK device as the "phone line" for a security alarm, it will be unusable as a regular Google Voice phone number, and it is not reliable enough to risk your safety. Alarm companies have now standardized on either a 4G wireless communicator, or an IP connection to the monitoring center, or both (one as backup).