I guess, same as on desktop. Do you have a device for it in xev/wev/xinput/swaymsg -t get_inputs/lsusb(?)/lspci/... is the device being set up sometime in journalctl -b0 (I guess you have systemd, right?) ?
When going deeper there probably are some other steps but initially think of it as if you booted a Linux on a laptop and its touchscreen didn't work. It might be the kernel in the end, but first go from the top down. Right now your WM does not get touchscreen events. So does your X/Wayland get the device? If not, get deeper. Yes, look around if it sends any events