BSS does not have CMS features. It’s a static front-end development tool.
If I wanted a way for users to add their own content to a website, I’d probably go with a platform that offers CMS features (ex. WordPress, Webflow, Squarespace, Wix)
There are posts in the forum discussing integrating third-party headless CMS solutions. You can search for them, or just seach Google for something like, “Add a CMS to a static website”
I was looking for the link to this post. Unfortunately the example site is gone, but the code still works.