J4.x:Adding a menu link in an article
From Joomla! Documentation
How to add a Menu Item from an Article
Joomla! allows you to add your articles to a menu without leaving the article itself. This feature provides an efficient way to speed up the process of publishing articles by removing the need to close articles to then go to the Menu Manager.
This tutorial covers the steps to add a menu item directly when an article is edited:
Edit an Article
Edit your article by:
- Going to Content → Articles and click on an existing one to edit it or
- Create a new one. See how to do this here: Adding a new Article.
Adding the Article to a Menu
Once you are ready to save your changes, choose the option Save to Menu
You will then be presented with the Menu: New Item page. Joomla will fill the Menu Title field but you can change it. Menu Item Type will already be set to Single Article. Remember to choose the correct Menu on the right for your item to appear in it.
Note: This tutorial covers adding a single article to a menu but you can also assign multiple articles to a Category Blog page by setting a specific category or sub-category.
Click Save&Close and you will be taken to the Menus: Items page for the menu you added the article to.
You should now see the article in the list of menu items.