The easiest way to host a static website, be it an SPA or just an HTML page, for the longest time was Github Pages.
But it has several serious limitations and I would avoid using it for a serious production project (hosting docs is fine though).
A decent alternative previously was Firebase Hosting, but now there's even better alternative.
There are many of them, but I want to highlight one of them - Vercel.
I've hosted a built static frontend in one click, for a few more clicks I've pointed it to a domain name that I own and it was free.