I don’t think this is the same tutorial that I was looking at earlier, but here is a tutorial about using Cloudflare for dynamic DNS updating in Yunohost. I’m sure there are plenty of other tutorials like this out there as well.
EDIT: Oh dear, I see that the tutorial I linked to is out of date. It made use of this script which, according to a PR in the script’s repo, “Cloudflare no longer accepts the old X-Auth methods and instead accepts just the key as an Authentication Bearer”. I’ll try again to find a suitable solution for using Cloudflare as DDNS for Yunohost.
EDIT: I found a recent post here on the Yunohost forums related to this issue, which may be of interest. The solution in that case was “to enable Full SSL Mode (end to end encryption), as I was on flexible mode before, which only encrypts the connection through cloudflare”. Might come in handy.
EDIT: Another related Yunohost forums post, this one is about issues with Let’s Encypt certs not auto-renewing when using Cloudflare, and there is a solution for this issue.