Custom theming: How to list multiple content types in the same page and use regions too I created two content types: articles and press releases and I want to display those in the same page. I also am developing a custom theme.

So I created a view for that with the machine name press_release_list, created a template for it: views-view--press-release-list.html.twig and it works perfectly. 

The problem is, I cannot make use of regions. I mean, I have content and side_menu regions and I want to add a twitter feed to the side menu. I add the block through "block layout" menu, it can be configured to be displayed on article and press release nodes however there is no option for the view I created...

I'm quite new to Drupal so what would be the best way to do this, is there a way to display the block on the view or is there a better option than creating a view?
In block layout the visibility for content types works only, if the content type is a route match. That means, you have requested a node with that specific content type through the url.

It does not work for nodes that are displayed as result of a view.

To configure the visibility for a view you can define in the tab "Pages" the url of the view or a pattern of urls, that matches multiple views.