Install
This is the repository archive. It installs, but the folder name will carry the branch suffix and updates will not flow.
Install straight from GitHub with WP-CLI:
wp plugin install https://github.com/salcode/wp-fast-login/archive/refs/heads/main.zipDo NOT use this plugin on a production website. This plugin should only be used on a local development site because it allows logging in as a user without providing the password.
This WordPress development plugin allows logging into directly from the login page (without entering a password or typing a username). The username is chosen from a drop-down menu.

Use as mu-plugin
This plugin can be used as a WordPress mu-plugin (for more information about mu-plugins see functions.php vs plugin vs mu-plugin for WordPress).
Copying the wp-fast-login.php into your wp-content/mu-plugin directory will add this as an active plugin to your WordPress site.
A quick way to add this file is to navigate to your mu-plugins directory and use this command to download the latest version of the wp-fast-login.php file.
curl -O https://raw.githubusercontent.com/salcode/wp-fast-login/main/wp-fast-login.php
Credits
Inspired By
Inspired by ServerPress's Bypass Login plugin.