how can I make this features posts widget?

Hi there,

The example site is using the WP Show Posts plugin:
https://wordpress.org/plugins/wp-show-posts/

The plugin will no longer be supported though as we've replaced it with the query loop block in the upcoming GenerateBlocks:
https://generateblocks.com/generateblocks-1-5-dynamic-data-query-loops-image-blocks/

It's currently in release candidate 2 so we are close to the official release.

Let me know if this helps :)

But how can i make it as sidebar? With the block element?

Yup or you can just use a block widget too.

I don't want to make it on all pages/posts.
I want to make it on specific pages.
how can I do that?
In addition, for cameras reviews for example I want to add pages that related to cameras and for
microphone reviews I want to add pages that are related to microphone is it possible?

I want to make it on specific pages.

In that case, a block element with display rules would work better.

In addition, for cameras reviews for example I want to add pages that related to cameras and for
microphone reviews I want to add pages that are related to microphone is it possible?

You might need a related posts plugin instead:
https://en-ca.wordpress.org/plugins/contextual-related-posts/

Thanks Leo!
Also, there's a way to make a post category the default post page?

I'm not sure unfortunately - not sure why there would be a need for that when there are post-category archives.

You could check with WP's support team though as that's not handled by the theme.