sysbird

“Posts Number Widget” the plugin display number of posts on widget.
<ul>
<li><a href="https://github.com/sysbird/posts-number-widget" rel="nofollow ugc">GitHub</a></li>
<li><a href="https://sysbird.jp/wptips/posts-number-widget/" rel="nofollow ugc">Description in Japanese</a></li>
</ul>
<h4>Usage</h4>
<ol>
<li>Add the “Posts Number Widget” for your widget area.</li>
<li>You can change the title and posts unit at settings.</li>
</ol>

Posts Number Widget

shazdeh

The shortcode requires the widget ID, but no need to guess, the plugin generates the code for you. To override the widget title for a widget you can use the “title” parameter: 
 [widget id=”text-1″ title=”New title”] 
You can also hide the widget title entirely if desired: 
 [widget id=”text-1″ title=”0″]
Additional Parameters:
<ul>
<li>container_tag: the HTML tag to use for the widget container, default: <code>div</code></li>
<li>container_class: CSS classname added to the widget container, default: <code>widget %2$s</code> (Note: uses sprintf for variable substitution)</li>
<li>container_id: HTML ID attribute for the widget container, default: <code>%1$s</code> (Note: uses sprintf for variable substitution)</li>
<li>title_tag: HTML tag to use for the widget title wrapper, default: <code>h2</code></li>
<li>title_class: CSS classname for the widget title wrapper, default: <code>widgettitle</code></li>
</ul>

Widget Shortcode

I had tried another plugin to use a widget in the gutenberg block editor on a page, however that plugin had some issues so was not ideal.

Widget shortcode enabled me to add my widget by copying the generated shortcode to the shortcode block in the block editor, resulting in the widget being displayed perfectly on the page. 

Works perfectly with the block editor

Adds [widget] shortcode which enables you to output widgets anywhere you like.

Posts Number Widget vs Widget Shortcode