Php 8.0.x Warnings

Seems like this plugin is not fully compatible with PHP 8.0.x! I am seeing the following warnings:

Warning Undefined variable $class_name1+wp-content/plugins/all-404-redirect-to-homepage/functions.php:77

Warning Undefined variable $class_name1+wp-content/plugins/all-404-redirect-to-homepage/functions.php:89

Php 7.4 has already reached end of life even for security support so we should be using php 8.0 which still has security support available. Can you please fix these warnings?

Thanks!