our samples contains login name requests because most of servers need it and send a request to enter the login name. Since your server does not need it, you can skip that step and make the Password: as your first step. Here is a code snippet that shows how to handle the screen you posted above.
Telnet telnet = new Telnet("server");
Scripting scripting = telnet.StartScripting();
// password prompt is not a regular prompt
// send first level password
scripting.SendCommand("first level password");
// here I believe that detect prompt can be used,
// or if you know that you will immediately send "enable" command
// you can read the prompt as a required text and not bother
// to set it as a prompt
scripting.ReadUntil("first level prompt"); // which ends with ">"
// if you connect to various devices with same behaviour but different
// prompt, but you want to skip to setsetting the first level prompt as
// discussed above, you can change ReadUntil argument to some regular
// uncomment this line if a regular expression is better way
// to handle various devices with different (but similar) prompts
// and comment out the 'scripting.ReadUntil("first level prompt");' line
// make sure that the regular expression describe your prompts correctly
// when you have first level prompt, send "enable" command
// password prompt is not a regular prompt, same as at the beginning
// send second level password
scripting.SendCommand("second level password");
// now detect prompt should work.
// since you may be using your own detect prompt you may need
// to call it instead of a rebex`s DetectPrompt
// do the work here...