Mikrotik has nothing built-in to server static files from a directory.
But, you can install nginx or lighttpd as a container, and use a mount to link the http server container’s www directory, to Mikrotik path.
A more modern approach might be use caddyserver container, slightly more complex in some ways, but deals with SSL certs more automatically & simplier if you need to proxy web traffic.
https://caddyserver.com with specifically
https://caddyserver.com/docs/caddyfile/patterns#static-file-server
For DNS, that be on you to define in your domain record so it point to VPS Mikrotik… or you can use the /ip/cloud name as the https:// host.