Request.Response ошибка 400 bad request

def pdf_http_response(file_body):
    # значение file_body вида "%PDF-1.5\r\n%\xb5\xb5\xb5\xb5\r\n1 0 obj\r\n<</Type/..."
    resp = flask.Response(file_body, status=200, mimetype='application/pdf')
    return resp
 
@app.route('/viewer', methods=['POST'])
def viewer_method():
    file_page = int(flask.request.args.get(u'numpage'))
    file_type = flask.request.args.get(u'type')
    file_data = flask.request.files[u'fieldNameHere']
    file_body = file_data.read()
 
    save_temp_file(file_page, file_type, file_body)
 
    resp = pdf_http_response(file_body)
    return resp

file_data = flask.request.files[u'fieldNameHere']

request.data

data = request.stream.read()

request.get_data()

data1 = flask.request.data дает # дает ''
data2 = flask.request.stream.read() # дает ''
data3 = flask.request.get_data() # дает ''

@app.route('/viewer', methods=['GET', 'POST'])
def viewer_method():
    file_page = int(flask.request.args.get(u'numpage'))
    file_type = flask.request.args.get(u'type')
    file_data = flask.request.files[u'datafile']
    file_body = file_data.read()
    file_decoded_body = base64.decodestring(file_body)
 
    save_temp_file(file_page, file_type, file_decoded_body)
 
    resp = pdf_http_response(file_decoded_body)
    return resp