Service Bill Attachment API InternalError

Hi Team,

We are working on attaching PDF files to Service Bills. But we are getting this error when we are testing the API:

array:2 [
  "Errors" => array:1 [
    0 => array:6 [
      "Name" => "InternalError"
      "Message" => "An exception was thrown that was not handled correctly. If this situation persists please contact developers@myob.com for further assistance."
      "AdditionalDetails" => null
      "ErrorCode" => 20
      "Severity" => "Error"
      "LearnMore" => null
    ]
  ]
  "Information" => "Warning, error messages have not been finalised in this release and may change"
]

Here is the sample POST payload that we are sending:

{
    "Attachments" : [
        {
            "OriginalFileName" : "NSW-1858631.pdf",
            "FileBase64Content" : "PCFET0NUWVBFIG...CjwvaHRtbD4K"
        }
    ]
}

We are using Laravel Framework at the backend if that would help. We are also setting the header Content-Type to `application/json`.

We are not sure how to proceed with this error. Can anyone please help? Thank you!