maxpagels

Direct link allows your post title permalinks to link directly to external sites. It can also be used to link to a particular page of your own site.

Direct link

Direct link allows your post title links to link directly to external sites.

Andrew Nacin

In WordPress 3.5, the Link Manager (which some use to build blogrolls) will 
be disabled by default. If you have links when you update, it’ll still be there. 
But you can use this plugin to ensure it will always be there, even if you 
update to a later version of WordPress or remove all of your current links.

Link Manager

Works on WP 6.1

Enables the Link Manager that existed in WordPress until version 3.5.

Direct link vs Link Manager