speedy222

Search every username in your WordPress site from the author. Make the WP Search Username Widget active in your Widgets menu from your WordPress site.
Or place the below shortcode in your WordPress site page content:
[search-username]
Or place the php shortcode in your themes file with a FTP Program. You can find the normal and php shortcode in your shortcodes.txt file.
Option author page with FTP:
Only if you have not a author.php page in your themes then you can upload the author.php page from your plugin directory with a FTP program and save it up your pc directory. And upload it to your themes /wp-content/themes/your-theme-name/ directory with a FTP Program.

WP Search Username

Search every username from the author in your Wordpress site.

Jason Coleman

Paid Memberships Pro

Kim Coleman

Andrew Lima

This plugin hides the “Display Name” field on the Edit Profile screen for all users. Instead of allowing users to set this field, the plugin will always set the User field display_name to their first and last name. If these field are empty, display_name will be set to their username.
Display names are set when the user registers as well as when a user’s profile is updated via the WordPress admin.
The plugin includes a batch process to update the display name for existing users. Navigate to Settings > Force First Last in the WordPress admin to run the update.

Force First and Last Name as Display Name

Thank you for this simple and effective solution. It is something that should be part of WordPress by default.
Cheers

Simple and effective

Force the user field "display_name" to be set as the user's first and last name.

WP Search Username vs Force First and Last Name as Display Name