title: how do I send a request using multipart/form-data?
body: <p>I have an app in ReactJs, using Axios and Papaparse.</p>
  
  <p>I have a page where a user drop a csv file in a box, I automatically download the csv, update and make some change in the data, and send a new csv file to a server.</p>
  
  <p>I did all until I arrive to the part where I need to create a new csv, and upload it to the server.</p>
  
  <p>Here is my code currently : </p>
  
  <pre><code>            const data = papaparse.unparse(destinationUpdateData, {
                  header: true,
                  skipEmptyLines: true
              });
              // data is a string in csv format
  
              const file = new File([data as BlobPart], "destination.csv",  { type: "text/csv" });
              // I get a File type.
  
              const paramsDestination = {
                  project_id: this.props.projectId,
                  datastore_id: 'DESTINATIONS',
                  file: file,
                  id: ["1", "2","3"]
              }
              // the data I would like to send is build
  
              Axios.post(`new_item_file_attachment`, params, {headers: {"Content-Type": "multipart/form-data"}})
              //I send to the server
  </code></pre>
  
  <p>The thing is, my server is expecting a request with a content Type of <code>multipart/form-data</code>, but I don't get how manually set my parameter to match this type.</p>
  
  <p>The api call currently don't work, because the data is passed like a json, and the server reject it. </p>
  
  <p>Is it possible to achieve it ? </p>
  
  <p>I tried using <code>FormData</code>, but I can't see how to send boolean and array</p>