@Aaron_Moreng you need to escape the JSOn and send it as a String, then deserialize it on the other side.
[\r\n{\"PartNum\": \"32247001\"},\r\n{\"PartNum\":\"45647010\"}\r\n]
So your JSON object you send to the function should look like
{
"soldToCustNum":8989,
"billToCustNum":8989,
.
.
.
"productList": "[\r\n{\"PartNum\": \"32247001\"},\r\n{\"PartNum\":\"45647010\"}\r\n]",
"ptAge":25
}
On the other side you’ll have to re-parse that field to turn it into an array