@freemo depending on your DNS provider, you can setup a redirect record. It is not an official standard but many providers allow you to do it (some call URL record, URI record, Redirect record).
But if you prefer or your provider doesn't offer you that, let me know and I issue a TLS for www and do the redirect on the server.
@freemo No, like I mentioned before: https://mastodon.social/@mastohost/100743608914197130 it really depends on your DNS provider the type of record to add.
I think you are using AWS to manage your DNS, if I am not mistaken in AWS it's the ALIAS record: https://aws.amazon.com/pt/premiumsupport/knowledge-center/redirect-domain-route-53/
Still, just let me know if you prefer to have me redirect in the server.