You can just create an index.html to get started without installing it.

see https://docsify.js.org/#/quickstart?id=manual-initialization

or usage https://github.com/docsifyjs/docsify-template

That's what I'm doing. But the site doesn't work. I guess the problem is something else.
Your site with documentation https://docsify.js.org/#/quickstart?id=manual-initialization doesn't work either (content is not rendered). Most likely because of a similar problem.

Check the console in the browser developer tool.

It seems that the reference of CDN resources failed.

Documentation site:

https://github.com/docsifyjs/docsify-template local serve:

The problem doesn't depend on location. Tried VPN with different IPs, your site with documentation https://docsify.js.org/ still won't open. I guess the problem is in the dependencies.

Problems with Vue?

see Console.

You may have some problems accessing https://cdn.jsdelivr.net/npm/docsify/ on your network.

Looks like a certificate problem, ERR_CERT_COMMON_NAME_INVALID.

But cdn.jsdelivr.net is not managed by us, so you may need to check your system or other issues.