Help in setup reverse proxy on OpenLiteSpeed (not from console)

Hi at all,
I'm trying to add reverse proxy to my virtual server, but I'm facing some issues with the configuration.
There are some guides on how to setup reverse proxy on litespeed, but they are for litespeed console (the one that runs at port 7080). On directadmin the console is read-only and I can't use it. I have to go with the manual way.

On my other server running directadmin on apache I just insert these parameters" and it works.
ProxyPreserveHost On
ProxyPass /
ProxyPassReverse /
RewriteEngine on
RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC]
RewriteCond %{HTTP:CONNECTION} Upgrade$ [NC]
RewriteRule /(.*) ws://$1 [P]

When I try to add it on my openlitespeed server in "custom httpd config" I have this errors :
[PlainConf] [] Not support [proxypass /] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:13
[PlainConf] [] Not support [proxypassreverse /] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:14
[PlainConf] [] Not support [rewriteengine on] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:15
[PlainConf] [] Not support [rewritecond %{HTTP:UPGRADE} ^WebSocket$ [NC]] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:16
[PlainConf] [] Not support [rewritecond %{HTTP:CONNECTION} Upgrade$ [NC]] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:17
[PlainConf] [] Not support [rewriterule /(.*) ws://$1 [P]] in file /usr/local/directadmin/data/users/admin/openlitespeed.conf:18

Like all my config is not supported on openlitespeed.

Can you give me an hint on how to setup the reverse proxy server on openlitespeed?