Show Query Loop of a specific category on page with text

Hello Support,

For days I’ve been struggling to setup a pretty ‘show posts’ instead of using the plugin WP Show Posts. I’m a little frustrated as this plugin is no longer supported, and GP/GB implemented it into its blocks, saying it’s 90% alike.

But what I can’t find – and I’ve read many articles about it – is the simple way of using a shortcode to put on a page which has already text on it. If I use the suggested Element and select the specific page, then on the front-end the text which was on the page disappears, as it is overruled by the Element.

With using the shortcode in WP Show Posts, I could set this below the existing text, so all text stays visible.
So, what I miss here is the option to set it ‘after_content’.

Another way could be to insert a Query Loop inside a container on the page, but then the problem is I don’t have the option to select a certain category, which is very important for this site.

So, I’m kind of stuck here.

An example of my page which shows in the grey block the GB container (which shows ALL posts), and the blue block shows the WP Show Posts, which only shows a certain category.
https://pijnmc.nl/behandelen/medicatie/

So, what do I need to do by using the GB (Pro) to make a simple list of posts of a certain category??

Thank you,
Yolanda