How to configure DDNS in Android? (IP needs to be updated often (VPN)

I use a VPN, without a static IP, as a result my IP address changes often. As a result of that, I want the IP I use to be linked to nextDNS, so everytime my IP changes, I have to manually select the refresh the linked IP option. And under the advanced settings DDNS is listed as a way to automatically update/link my IP. But I don't see any guides anywhere showing how to do that for Android. I did however see fine print that said DDNS configuration is not recommended on mobile devices. If that is true, why is it not recommended?