So…I am using this router with Starlink. Since they use CGNAT, I don’t have a public IPV4 address. I enabled IPV6 on the router and bypassed the Starlink router. The MT3000 reports that I have an IPV6 address that I assume is public.
I tried to set up DDNS in Luci. I installed, the requisite scripts, except for NO-IP.pl which Luci complains is not installed. I cannot find that script in software repositories.
You also need to change DNS settings to manual in the GUI then you should be able to make changes in LuCi. Also Check edit host on the GUI DNS page should only be the ones you want.