You don't need a static IP, you just have to keep track of what your current dynamic IP is.

You can do this with either a free or a paid DNS service.

There are a few different 'free dns' services that will delegate a subdomain of theirs to you at no cost. Admittedly, I've never actually used one of these so their names escape me. Hopefully someone else can point one of those out if that's what you really want.

I purchased a domain via google domains, when they existed. It's now transferred to squarespace, because they bought out google domains a few years ago.

It was around $13/year when I first got it a decade ago. It's now around $28/year.

This allows me full control over the domain: I can use as many subdomains as I want to give each service I use it's own unique name. (Instead of using their own separate ports that you've gotta remember) My domain will also forward all inbound email to my gmail account; this lets me use email addresses like <servicename>@mydomain.example. This way, I don't share my real email and can immediately tell who sold my info to the highest bidder when I get spam. (I could also host my own email service if I really wanted, but I haven't bothered)

Add Cloudflare ontop (for free); and it can filter out known attacks, ddos attempts, geofence your services to regions you'll actually be in, provide/autorenew ssl certs for https, show you usage analytics, cache static data reducing server/network load, etc.

Ultimately, the paid option is well worth it IMO. $2/month (which I typically pay in 3-10 year blocks) is hardly anything.

/edit; vpns are good and all, but they require you to setup software on the remote device to connect to it, and that typically routes most if not all your traffic back to the vpn server then out to the internet. That can create speed/bandwidth issues.

A domain allows you to access your services from any Internet connection with 0 configuration on the client side. Just accessing it like any other website.

I also host a vpn directly from my network, that I access/find via my domain. This means I'm not dependent on a public service like tailscale, but can still add additional security to access private only services (stuff I don't expose to the open internet)