POSTing a document to GeoNode through REST API returns JSON parse error

Question

We are trying to POST a document to GeoNode through its REST API. Here is the code. The error returned is that JSON parse error.

I have tried many ways of sending the fileObject - a string, blob and file, but the same error pops up. Anyone can advice me what could be the issue?

    //now to send the document upload in geonode
    let url = 'https://DOMAIN/api/v2/documents/';                
    var crf_token1 = $('[name="csrfmiddlewaretoken"]').attr('value');
    
    var fileK = document.querySelector('#fileInput');  // the geojson file we uploaded
           
    let headers = new Headers();
    //headers.set('Authorization', token.token_type + ' '  + token.access_token);  //+ ' ' +
    headers.set('Content-Type','application/json');  
    headers.set('Accept','application/json');       
    var crf_token = $('[name="csrfmiddlewaretoken"]').attr('value');
    headers.set('X-CSRFToken', crf_token);
    
    var formData = new FormData();         
    formData.append('file', fileK.files[0]); //jsonobject); //jsonobject); //fileK.files[0]); // read.result ); // blobD read.result //fileD); //fileF) //myFile) //fileX) //myTestFile) //myEncryptedFile) //global_finalEncryptedZipFile)       
     //document related parameters        
     formData.append('owner', 'admin');             formData.append('title', 'testdoc');
     formData.append('abstract', 'testdoc');        formData.append('attribution', 'test');
     formData.append('bbox_polygon', 'MULTIPOLYGON (((0 0, 0 1, 1 1, 1 0, 0 0)))');
     formData.append('constraints_other', 'no');    formData.append('data_quality_statement', 'no');
     formData.append('doi', 'test');                formData.append('embed_url', 'test');
     formData.append('is_approved', 'true');        formData.append('is_published', 'true');
     formData.append('ll_bbox_polygon', 'MULTIPOLYGON (((0 0, 0 1, 1 1, 1 0, 0 0)))');
     formData.append('maintenance_frequency', '1'); formData.append('metadata_only', 'true');
     formData.append('popular_count', '1');         formData.append('share_count', '1');
     formData.append('srid', '1');                  formData.append('purpose', '1');         formData.append('rating', '1');
     formData.append('language', 'English');        formData.append('supplemental_information', 'No information provided');
     formData.append('temporal_extent_end', '2022-02-02 12:21');         formData.append('temporal_extent_start', '2022-02-02 12:21');
     formData.append('thumbnail_url', 'test');      formData.append('Regions', 'Global');
     formData.append('Responsible', 'admin');       formData.append('date', '2022-02-02 12:21');
     formData.append('edition', 'test');            formData.append('date_type', 'test');       
            
    fetch(url, 
              { 
                   method:'POST',
                   credentials: "same-origin",
                   headers: headers ,
                   body: formData // jsonobject //formData  //fileK.files[0]       
              }
         )
        .then(response => response.json())
        .then(json => console.log(json));

When I try to upload a word document, the error returned within the browser console is

{detail: "JSON parse error - 'utf-8' codec can't decode byte 0xd2 in position 226: invalid 
continuation byte"}

When I try to upload geojson file, the error returned is

{detail: 'JSON parse error - Expecting value: line 1 column 1 (char 0)'}