Ddns with TSIG, how to call ddns.myddns_ipv4.update_script with interface?

I’d like to do a dynamic DNS update using tsig )see Using nsupdate for dynamic DNS TSIG Updates)

While I found how to set


I had to hard code the interface in the script.
I’d rather pass the interface to update as anargumen, as such

# /usr/bin/nsupdate-home-router.pcfe.net-tsig eth1

how do I do that?