How to send extra custom headers to backend server?

There are standard headers for Reverse Proxy HTTPS traffic, such as “X-Forwarded-For” and “X-Forwarded-Proto”. LiteSpeed ADC adds these request headers as well in order to pass information to the origin backend web servers. Be careful when using these headers on the origin server, since they will contain more than one (comma-separated) value if the original request already contained one of these headers.

If you need to specify custom request headers to be added to the forwarded request, you can use configuration directive similar to Apache's mod_headers RequestHeader directive in the “Extra header” configuration field to add custom request headers.