Kristopher Lagraff

This plugin enables the short link menu item to display in the admin toolbar. This feature was removed from 
version 3.3 by default.

Reenable Shortlink Item In Admin Toolbar

This plugin will display the shortlink menu item in the admin toolbar.

Chip Bennett

Mark

WP-Short.io is the easiest way to generate short links for your WordPress posts. It is a timesaving integration since you don’t need to copy a long link and manually shorten it on Short.io.
Specify an API key (you’ll find it in your Short.io account), identify the post types to create short links for, and forget about it! WP-Short.io automatically shortens URLs for WordPress posts.
After you finish writing a striking post, share it with your friends on social media.
Now, instead of a long URL, a short and automatically generated link is already waiting for you. Just copy and send it!
Feature Requests are welcome via https://feedback.short.cm/

short.io

Use short.io generated shortlinks for all your WordPress posts and pages, including custom post types.

Reenable Shortlink Item In Admin Toolbar vs short.io