Server connect form not passing on variable data to API Action

I apologize for the very elementary question I am about to ask…

I cannot seem to get a post variable to be passed along to my API call. Quick background - setting up Backendless to be able to manage users more effectively out of the box and set up social auth. Calling the API that inserts a user without variables works perfectly. i.e.,

jsonData like so:

{
“name”: “Fake User”,
“email”: “fake@gmail.com”,
“password”: “123456789”
}

However, when I update to using the variable from the POST form I get a null value for the name:

{
“name”: “{{$_POST.inp_name}}”,
“email”: “fake@gmail.com”,
“password”: “123456789”
}

Am I missing something on how to add a form variable to the JSON data?