Token Authentication v1.0 using Postman

When I submit a POST to
url: https://www.humanity.com/api/
Parameters: None
Authorization: None
Headers: None
Body: Raw JSON:

{
"key": "my key",
"module": "staff.login",
"method": "GET",
"username": "my username",
"password": "my pw"
}

All I get is an error (Unexpected '<'). Am I missing something? Or is my setup incorrect?

Appreciate the help!