Phone has no dial tone
Our business phone has not had a dial tone for some time. Our building is closed currently, but the office still needs to operate. Internet is working fine and incoming calls reach voicemail successfully, but there's no way to make outgoing calls or pickup incoming calls. We have several routers and modems stationed in the office, but I'm not certain which requires a reset as the phone itself does not plug into any of them directly. Any help on how to proceed would be appreciated.