Running script on Tun0 up


I am trying to run a small script after i connect to a vpn server.

My understanding was that putting a executable script in
/etc/network/if-up.d would run the script after a network interface is created.

reference the hook script parts:

just for test purpose i put the scrip in /etc/network/if-ip.d


echo “tun0 up” >> /var/log/tun-up.log

when i connect the vpn nothing get written in the log.
I am on the right track? or all of this is wrong.

For info this is on Debian 10
im calling the vpn using the command
systemctl start [email protected]
the vpn work just fine

Any help would be greatly appreciated!