[Questions]: Download default assets in manager on init

1. I'm trying to implement an example as in a demo, namely: when clicking on a background image installation, a window pops up offering you to download files or select from already downloaded ones. Uploading to the server I successfully implemented, the files are loaded, saved in the desired folder, after they appear in the list of assets on the right, which you can click and apply to the background. But when updating the page and repeating all the above manipulations, the asset manager (the one on the left is empty).

As an example, by default, assets are specified as in the demo example (that is, pre-defined pictures with placehold.it), but again, the asset manager is always empty when opening.

The console displays a gjs-nl-asset with a list of specific images, but there are none in the resource list.

2. When opening the asset manager on the left, there is always a single semi-transparent image that I did not ask or load. How to remove it

3. For example, if you try to set a background image for "body", when you click on the icon with the plus of adding a background image, the message pops up in the console of the form htttp: //mysite.com/none, with the status 404 (Not Found) grapes.min.js:11 , so I understand that there is an attempt that download and what is not clear

I ask for help. Спасибо, Артур