How To Send Messages To The LTE Shield With TCP (Not Hologram)?

I’m trying to communicate with the LTE shield with a custom TCP server instead of the Hologram dashboard. I have been able to send data from the shield to the server, but I can’t seem to figure out how to receive messages from the server, since the server doesn’t really know where to send it to. I tried sending the message back through the same socket that the server received messages from, but that didn’t seem to work. Any suggestions?