Creating a new record from a 3rd party online form

This is what I am trying to do.  We use FormAssembly to collect data in an online form that we host on our website.  FormAssembly has an HTTP Connector that I would like to use to post the data directly into a custom record I have created. Looking at the documentation on both ends it seems like it should be  possible by creating a NetSuite Custom Online Form and then Posting the data from the Form Assembly form.


If I try this using the  NetSuite External form URL I get the error below:

Please review the error(s) below.
•An error occured while submitting the data to a third-party service. The error returned is: 405 Method Not Allowed Error 405--Method Not Allowed From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1: 10.4.6 405 Method Not Allowed The method specified in the Request-Line is not allowed for the resource identified by the Request-URI. The response MUST include an Allow header containing a list of valid methods for the requested resource.