Here's how I got the sign working on Debian.
This assumes the sign is at 10.164.3.85 and is connected via ethernet (e.g. enp0s25).
# set up address on same subnet to talk to sign (e.g. increment the last octet).
# Use interface name for your ethernet port
sudo ip addr add 10.164.3.86/24 dev enp0s25
# install perl deps
sudo apt install libmodule-build-perl libdigest-crc-perl
# not sure what this stuff is doing
perl Build.PL
./Build installdeps
./Build manifest
# write to the sign (edit the script to use the correct ip address)
perl signserver.pl