hi, you did not reply to my question.
I’ll detail it better.

Look at the image attached “shop”.
You can see (https://staging.acinolilla.com/shop) that I created the hidden sidebar for filters, actually empty.
The question is: how can I add the filters in this hidden sidebar? adding widgets? adding an HTML block?

Look now at the image attached “widgets”.
I created some test filters as widgets, as you can see in the image attached, in different widgets shop areas, but nevertheless they are not displayed in the hidden sidebar.

So, the main question always is: how can add the filters in the hidden sidebar?

A problem in the problem is that in the widget area “shop page widget area” I added a widget that I cannot be deleted, as the “delete” menu item is missing. Look always at the image attached “widgets”.
How can I delete this widget?

I attach also the admin credentials in case you want to look with your eyes what I wrote.