window.open equivalent to axios Sending post data

I made the data with FormDta

  var url = `/myapi`;

  var formData = new FormData();        
  formData.append('metadata',JSON.stringify(export_param));
  var dataurl = imagePreviewRef.current.makeImageDataUrl();
  var blobData = createBlob(dataurl);
  formData.append("file",blobData);

   axios.post(url,formData
    ,{headers: {'Content-Type': 'application/form-data'}}).then(res=>{});// it works

It works well so I want to replace the axios post to window.open

  window.myWin = window.open(url,"mywin",'status=yes,width=800,height=600');

However how can I pass the POST data to this window.open??