I'm not a nextcloud user but have a homelab and use traefik for my reverse proxy which is configured to use letsencrypt dns challenges to issue wildcard certificates. I use cloudflares free plan to manage dns for my domains, although the registrar is different. This has been a set it and forgot solution for the last several years.

Let's Encrypt cert renewal comes out of the box on traefik? I haven't kept up with it. I'm on a similar set and forget schedule with configured nginx and some crowdsec stuff, but the API change ended up killing off an afternoon of my time.