phpBB Fixed footer navbar Extension

Install

Download the latest release.
Unzip the downloaded release, and change the name of the folder to fixedfooternavbar.
In the ext directory of your phpBB board, create a new directory named dmzx (if it does not already exist).
Copy the fixedfooternavbar folder to /ext/dmzx/ (if done correctly, you'll have the main extension class at (your forum root)/ext/dmzx/fixedfooternavbar/composer.json).
Navigate in the ACP to Customise -> Manage extensions.
Look for Fixed footer navbar under the Disabled Extensions list, and click its Enable link.

Navigate in the ACP to Customise -> Extension Management -> Extensions.
Look for Fixed footer navbar under the Enabled Extensions list, and click its Disable link.
To permanently uninstall, click Delete Data and then delete the /ext/dmzx/fixedfooternavbar folder.