$ telnet --help
telnet: invalid option -- -
Usage: telnet [-4] [-6] [-8] [-E] [-K] [-L] [-X atype] [-a] [-d] [-e char]
[-l user] [-n tracefile] [-r]
[-z ssl] [-z secure] [-z debug] [-z verify=int]
[-z cert=file] [-z key=file]
[host-name [port]]

You pretty much want to run `telnet -l my_desired_username hostname`
where my_desired_username should be obvious, and hostname is whatever you're already typing in as the server name.

P.S. And yes, I know that --help was not a valid option, but it got the answer . I'd really recommend reading the man page .