fatal error and php 8 deprecation notices

The site was crashing today with a fatal error. It looks like it was this plugin with the latest .18 release: [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$api_key is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 46 [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$twoinc_search_host_no is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 47 [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$twoinc_search_host_gb is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 48 [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$twoinc_search_host_se is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 49 [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$twoinc_checkout_host is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 50 [07-Dec-2023 19:39:54 UTC] PHP Deprecated: Creation of dynamic property WC_Twoinc::$plugin_version is deprecated in /home/sitename/public_html/wp-content/plugins/tillit-payment-gateway/class/WC_Twoinc.php on line 52 [07-Dec-2023 19:39:55 UTC] PHP Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, non-static method WC_Twoinc::on_order_bulk_edit_notices() cannot be called statically in /home/sitename/public_html/wp-includes/class-wp-hook.php:324 Stack trace: #0 /home/sitename/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() #1 /home/sitename/public_html/wp-includes/plugin.php(517): WP_Hook->do_action() #2 /home/sitename/public_html/wp-admin/admin-header.php(303): do_action() #3 /home/sitename/public_html/wp-admin/admin.php(239): require_once('/home/sitename...') #4 {main} thrown in /home/sitename/public_html/wp-includes/class-wp-hook.php on line 324 A lot of plugins are throwing these deprecation errror in PHP 8.x but the fatal error at the end took out parts of the website.