Http2 not working with haproxy

i want to configure haproxy with http2 so i have enabled “bind :::443 v4v6 ssl crt /etc/httpd/ssl/dissin.pem alpn h2,http/1.1” parameter in haproxy.

next i have configured http2 protocol in apache without haproxy it is working fine . (e.g) “GET /icons/poweredby.png HTTP/2.0” 304"

  1. i want know how to enable http2 protocol in haproxy,
  2. since my ssl avialable in haproxy backend servers listens port 80. without ssl http2 will work
    please some one help me configure to http2 along with haproxy

Please note that HTTP2 works with SSL so servers listening to http will not speak http2.
below configuration works for me.
bind *:443 ssl crt /etc/ssl/certs/domain.pem alpn h2,http/1.1