HAProxy to v2ray

I have a VPS with v2ray that is proxied behind Cloudflare. Because of the restriction of open ports of Cloudflare, I want to use HAproxy to connect all users via the 443 port on VPS. How can I configure HAproxy to implement such a scenario? Is there something I should do on v2ray and x-ui too?

I really appreciate any help you can provide.