iPhone 13 pro won't connect to cellular

So, more than likely this is not so much a “replace” as a repair. Nearly all iPhones starting with the iPhones X make use of a dual board design. The logic board is actually two separate boards stacked on top of each other sandwich style, with an interconnecting board between.

The bottom of the two boards is where cellular components are located. In cases of damage, especially with glass shatter, or when the housing might bend, a separation between the top and bottom may occur, or the solder pads holding them to the interconnect board tear off, severing the connection in some places. Are you able to see things like the device IMEI, or modem firmware in settings? (Would be under General > About). If not, this sounds like a dead ringer for a board issue.

This can be repaired, but it requires lots of soldering know how. You would have to split the boards and repair any damage by running micro jumpers, or building new pads. If you cannot do this yourself, I recommend seeking a shop who does board repairs to assist.