CFHTTP JSON request with file attachment(s)

Hi All

I’ve been using Lucee to send JSON api calls to a third parties system typically like below:

<cfset sms_message1 = {
} >

<cfset sms_message = Replace(serializejson(sms_message1),"","",“ALL”)>

< cfhttp name=“simwood” method=“post” url=“”>
< cfhttpparam type=“body” encoded=“yes” value="#sms_message#">
< /cfhttp>

Which works perfectly to send SMS messages.

However, to send a fax via this API I need to attach PDF file(s) to the API call. The instructions for this call are below. I’ve now tried for several days and am getting knowhere. Any help gratefully received!

Here’s the instructions: