Document upload: UnsupportedContentType

i tried uploading a document through dwolla api library

const Client = require('dwolla-v2').Client;
const fs = require('fs');
const dwolla = new Client({
        environment: "sandbox",
        key: "key",
        secret: "secret",
      });

    const customerUrl ="https://dashboard-sandbox.dwolla.com/customers/c1ba3805-9232-4ffe-a866-3fa60ea0cf60";
    const requestBody = new FormData();
fs.readFile('icon.png', function(err, data) {
  if (err) throw err;
  if(data){
    requestBody.append("file",new Blob([data]), {
      filename: "document.png",
      contentType: "image/png",
      knownLength: fs.statSync("document.png").size,
    });
    requestBody.append("documentType", "license");
  }
});
    
    dwolla.post(`${customerUrl}/documents`, {
      body: requestBody,
      headers: {
        'Content-Type': 'multipart/form-data'
     }
    }).then((res) => res.headers.get("location")) // => "https://api-sandbox.dwolla.com/documents/fb919e0b-ffbe-4268-b1e2-947b44328a16"
    .catch((err) => {
      console.error(err.body);//error codes
    });

and i got an error like this:
{
code: ‘UnsupportedRequestContentType’,
message: ‘Invalid request Content-Type. multipart/form-data.’
}
i have confirmed that the document is loaded and in the right directory

Hi @aebydeen , We’ll work on getting an example updated in our documentation, in the meantime, could you try modifying your request to match this example to see if that fixes the issue?