Below is how the users.txt file works:
"Users"
{
"superadmin"
{
"YOUR NAME HERE" "STEAM ID HERE"
}
"admin"
{
}
}
So for example:
"Users"
{
"superadmin"
{
"Nick" "STEAM_0:1:8002048"
}
"admin"
{
}
}
Replace "STEAM_0:1:8002048" with your real steam ID, you can get your steam ID by starting a listen server with your client and typing "status" in the console.