Christhian Gruhh

With the Use Hashtags plugin, you can easily use hashtags in your content (and your excerpt). Just type # plus a word, and the plugin will automatically convert it to a link.
The link send the user to the website search page, showing additional content that also uses that hashtag.
This can enhance the user experience, as it creates a new navigation layer inside your content.
<ul>
<li>There is no need to maintain the hashtags, just add them to your text, and it’s done.</li>
<li>This plugin is non-destructive, so it does not make any changes to how your content is saved. Only when the content is presented, the link will appear for the visitors.</li>
<li>This plugin does not generate external links.</li>
<li>Tested with selected core blocks.</li>
</ul>
Tested with popular themes:
<ul>
<li><a href="https://wordpress.org/themes/twentytwentytwo/" rel="ugc">Twenty Twenty Two theme</a>.</li>
<li><a href="https://wordpress.org/themes/twentytwentyone/" rel="ugc">Twenty Twenty One theme</a>.</li>
<li><a href="https://wordpress.org/themes/generatepress/" rel="ugc">GeneratePress theme</a>.</li>
<li><a href="https://wordpress.org/themes/neve/" rel="ugc">Neve theme</a>.</li>
<li><a href="https://wordpress.org/themes/hello-elementor/" rel="ugc">Hello Elementor theme</a>.</li>
</ul>

Use Hashtags – convert #hashtags to search links

Use #hashtags as part of your content, and improve your UX.

Kyrie

“Characters starting with #” will be tag links. 「#から始まる文字」がタグリンクになります。Like Instagram. Like note-mu. Mobile-Friendly. You can choose whether to save tags in post.
<pre><code>this #sampletag are displayed as a posted tag link.
↓
this <a href="tag/sampletag">#sampletag</a> are displayed as a posted tag link.
</code></pre>
<ul>
<li>
You can choose whether to save tags in post. タグを投稿に保存する/しないを選べます。
</li>
<li>
You can specify the maximum number of characters in which hash tags are recognized as tags.(the initial value is 15)(Unlimited at 0) 
タグとして認識する最大文字数を指定できます。(デフォルトは15、0は無制限)
</li>
</ul>
These are not recognized 
 * Characters beginning with two or more #(##example) 
 * HTML color codes(ex.#cccfff) 
 * Only numeric(ex.#123456) 
 * 
複数シャープから始まるタグ、カラーコードに該当するタグ、数字のみのタグなどは認識しません。元々リンクして書かれている場合も書き換わりません。
You can escape beginning with minus -(-#example) 
マイナスを付けると、タグにもリンクにもならず、マイナスが除去された #文字列 となります(エスケープ)
Other examples 
<a href="https://kyrie.cloud/web/1306#i-3" rel="nofollow ugc"> https://kyrie.cloud/web/1306#i-3</a>
This is Mobile-Friendly plugin. 
 シンプルな設定画面なのでスマホからも設定しやすいです。
<h3>bug report</h3>
<a href="https://kyrie.cloud/web/1306" rel="nofollow ugc"> https://kyrie.cloud/web/1306</a>

Hash Hash Tags

"Characters starting with #" will be tag links. 「#から始まる文字」がタグリンクになります。Like Instagram. Like note-mu. Mobile-Friendly.

Use Hashtags – convert #hashtags to search links vs Hash Hash Tags