by Sridhar Katakam on WordPress.org
Adds the missing WordPress admin bar in WordPress Gutenberg editor when it is fullscreen.

Before
When a new Page or Post is being edited in the WordPress Gutenberg editor in Fullscreen mode the WordPress admin bar aka The Toolbar will not appear by default.
This plugin fixes that and shows the admin bar even when the WordPress editor is Fullscreen.
There are no settings for the plugin. Just install and activate.
Search for admin bar fullscreen from within your WordPress plugins’ Add New page and install.
Download button to download the plugin.admin-bar-fullscreen-mode folder to the /wp-content/plugins/ directory.Plugins menu in WordPress.