The correct method for loading custom modules typically involves DKMS to automate building and signing procedure for the current kernel.
Loading kernel modules and creating character files is recommended to perform like this:
sudo tee /etc/modprobe.d/muxponder.conf << EOF > /dev/null
options gendrv \
devices=1 \
base=00000000 \
irq=-1 \
description=digi0:pci?(1.0.0.0)+0:7ffffff:32:2 \
shared_mem_start=0x040000000
EOF
sudo tee /etc/modules-load.d/muxponder.conf << EOF > /dev/null
gendrv
EOF
sudo tee /etc/tmpfiles.d/muxponder.conf << EOF > /dev/null
c /dev/digi0.S - - - - 235:0
EOF
sudo systemctl restart systemd-modules-load.service
sudo systemctl restart systemd-tmpfiles-setup-dev.service
We can provide more specific instructions if you post a link to the driver source code.