get https://example.com/v1/submission
This method returns a single submission collected for a form.
Get the specified submission
GET /api/v1/submission?api_key=[[app:api_key]]&id=12345 HTTP/1.1
Host: www.formstack.com
curl -i "https://www.formstack.com/api/v1/submission?api_key=[[app:api_key]]&id=12345"