Nginx rewrite issue

[Dr_tux]

Hello, 

I want to write a rewrite like http://url/index.php?target=server1 and
http://url/target=server1 in Nginx and I want to use it in reverse proxy.
This is possible in AWS, but how can I do it in Nginx?

I tried as follows. Not worked.

location = /index.html?target=server1 {
  proxy_pass http://server1;
}

location = /index.html?target=server2 {
  proxy_pass http://server2;
}

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,293708,293708#msg-293708