Issue with the staff.login module

Hi there,

I can't seem to get a successful response even after using the right credentials, and I keep getting the following error message:

{"status":98,"data":"Bad API Paramaters - Invalid POST request. See Manual.","error":"no post data","token":null}

I send a POST request to the following URL https://www.humanity.com/api/
with the following data:

{
"module":"staff.login",
"method":"GET",
"request":{
"key":"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
"username":"[email protected]",
"password":"xxxxxxxxxx"
}
}

Is there something I'm doing wrong?