We need solution for user:pass auth for users dashboard and then sessions generator for upstreams.
You also need a limit on the amount of traffic for this user

Or just setup openresty and nginx,
One port for http\https, then after user:pass auth will redirect for example from nginx_ip:user:pass:upstreamname:port:1000 to external IP:port 20001
nginx_ip:user:pass:upstreamname2:port:1001 to external IP:port 20002
and etc

Please contact to TG:
https://t.me/TheSocks5