Warning: Undefined array key "HTTP_X_SELLIX_SIGNATURE" in /usr/www/infamousark/twitch/webhook/test.php on line 4

Fatal error: Uncaught TypeError: hash_equals(): Argument #2 ($user_string) must be of type string, null given in /usr/www/infamousark/twitch/webhook/test.php:7 Stack trace: #0 /usr/www/infamousark/twitch/webhook/test.php(7): hash_equals() #1 {main} thrown in /usr/www/infamousark/twitch/webhook/test.php on line 7