odoo multifile upload

controller.py

class MainController(http.Controller):
    @http.route('/photo_upload', type='http', csrf=False, auth='user')
    def photo_update(self, **kwargs):
        Ira = request.env['ir.attachment'].sudo()

        //img1
        image_buffer_random = kwargs['avatar'].stream.read()
        image = base64.b64encode(image_buffer_random)

        //img2
        image_buffer_random2 = kwargs['avatar2'].stream.read()
        image = base64.b64encode(image_buffer_random2)

upload.js

$('button').click(function(){
  var files = $('#avatar').prop('files');

  var data = new FormData();
  data.append('avatar', files[0]);
  data.append('avatar2', files[0]);

  $.ajax({
      url: '/api/upload',
      type: 'POST',
      data: data,
      cache: false,
      processData: false,
      contentType: false
  });
});

@ruter