Show categories in page

Hello,
I saw your demo that shows 4 categories with files inside and I couldn’t make my web page like yours.
I couldn’t find how can I insert a specific category.
In forum I found a shortcode
`[wpdm_category id="φυλλάδια" operator="IN" title="Custom Title Here or 1" desc="Custom Description or 1" toolbar="1" paging="1" orderby="field name" order="asc or desc" items_per_page="10" template="page-template-default" cols=4 colspad=2 colsphone=1 async=1]
but it just shows the search tab and page-template-default.php below.
Can you tell me what am I doing wrong?

I already saw that documentation, this is where I got the shortcode.
The page that I test your plugin is https://www.lamitec.gr/testing-page/
Also the page-template-default is the id that it shows me in templates.
I want to make something like the demo page you have https://try.wpdownloadmanager.com/ where are 4 folders “Documents”, “Free Downloads” etc…

I found why i didn’t show me the files. I had to put the template id with .php in the end.
I cannot find how you made the demo page with the folders (documnets,free downloads…) is this a plugin or a way to show the categories?
Can you tell me how you done that?

I already download this as well but my problem is that the template I have is using wpbekry and not Gutenmberg blocks so I can’t use it.
I tried to use guetnberg editor as default editor and also a new component in wpbakery that utilizes gutenberg editor put when I insert the category cards it says “This block has encountered an error and cannot be previewed.”