Hello,
It seems that with the OPNsense 23.7 release or at a later date the os-dyndns plugin is no longer supported or even deleted.
It is advised to use the os-ddclient plugin. However, you cannot specify the interface or gateway "WAN Failover" as "Interface to monitor" there. But this works with the plugin os-dyndns.
My question now: How and with which DynDNS plugin can I achieve that it is always searched via the gateway "WAN Failover"?
Many greetings
Martin
Have a look at this:
https://forum.opnsense.org/index.php?topic=34139.msg169680#msg169680