Connect a custom domain
Your exported site lives on whichever host you choose, so your domain points at that host rather than at PortfolioDIY. The pattern is the same almost everywhere: add the domain in your host, then add the DNS records your host gives you.
You'll need a deployed site (see the GitHub Pages tutorial) and access to your domain registrar's DNS settings.
In this tutorial
Buy the domain
Any registrar works — the only requirement is access to the domain's DNS settings. Prefer a name you'll still want on a CV in ten years; yourname.com or yourname.dev ages better than a pun.
Tell your host about the domain
In your host's dashboard, find the custom domain setting: on GitHub Pages it's under the repository's Settings → Pages; on Netlify and Cloudflare Pages it's under Domain settings; on cPanel it's Addon Domains.
Enter your domain. The host will then show you exactly which DNS records it expects — usually a CNAME for the www subdomain and either A records or an ALIAS for the bare domain.
Add the DNS records at your registrar
In your registrar's DNS panel, create the records from the previous step. The names and values must match exactly — a trailing dot or a typo'd target is the most common failure.
DNS changes propagate in minutes usually, but can take up to an hour. If the host still reports "not configured" after that, re-check the record type: apex domains can't use CNAME records at most registrars, which is why hosts publish A/ALIAS alternatives.
Enable HTTPS
Once the domain resolves, switch on the host's HTTPS option — GitHub Pages calls it "Enforce HTTPS", Netlify and Cloudflare do it automatically. Certificates are issued for free within minutes.
Finally, set your canonical URL: in the editor's SEO settings, set the base URL to your new domain and re-export, so your sitemap and structured data reference the real address.
Tip: Redirect www to the bare domain (or the reverse) at the host level so you present one canonical address everywhere.
Reference-style reading instead? See the documentation.