Using proxy_redirect correctly

Hi all,
My proxy seems to be working, at least so far. I browse to
and find the OSTicket installer. Since I’ve removed the OST site from
Nginx, I know Apache is kicking it like it should be. The only problem
is that OST thinks its location is, which is the internal
redirection but not what I want it to use.

I know I have to use proxy_redirect, but I don’t quite understand how
directive works. I just tried:
but that didn’t work. I find the documentation I’ve read thus far to be
rather confusing. All I want to do is replace in any URL
this site with Do I need some kind of regular
To move this proxy somewhere else (currently it’s in location /
Should my proxy_pass also be moved to a different context?