How to password protect http proxy?

Question

VPN

Good day!
I'm sorry that maybe I'll ask you if I need to drown something, I'm in touch)
This kind of task ... You need to protect the http proxy with a password.
There is a Debian server on it with OVPN installed
and ports and accesses configured through IPtables.
With the part of the server, everything is ok and everything works, there is a second side, this is a mobile device from which we make a Proxy Server for sale to customers or for personal use, OVPN Client and Socks Server Ultimate are installed on the phone with the help of the latter, proxies are raised Be it Socks5 be it Http. ..
But either I don't fully understand Socks Server Ultimate ... or I need to approach the issue differently, I can't protect the http protocol with a password to ensure protection from a banal brute.
p/s when raising socks5 there is a user field ..
Or maybe someone will tell you, Server on Android with the ability to raise HTTPS proxy With authorization