Please visit URL

Plugin version 1.4.1

231 if ( $core_updated || $plugins_updated || $themes_updated ) { // Did anything come back as need updating?
232 $message = __( “There are updates available for your WordPress site:”, “wp-updates-notifier” ) . “\n” . $message . “\n”;
233 $message .= sprintf( __( “Please visit %s to update.”, “wp-updates-notifier” ), admin_url( ‘update-core.php’ ) );
234 self::send_notification_email( $message ); // send our notification email.
235 }

This emails:

“””
There are updates available for your WordPress site:

Plugin: Wordfence Security is out of date. Please update from version 5.0.4 to 5.0.5
Details: https://wordpress.org/plugins/wordfence/
Changelog: https://wordpress.org/plugins/wordfence/changelog/
Compatibility: Compatibility with WordPress 3.9: 100% (according to its author)

Please visit https://example.org/wp-admin/update-core.php to update.
“””

You should add/change that URL to /wp-admin/plugins.php in case there is plugin updates available. Maybe even only print it when there is no core updates.

https://wordpress.org/plugins/wp-updates-notifier/