catfact.php

<?php
session_start();
header("Content-type: application/json; charset=utf-8");
$username = !empty($_POST["username"]) ? strtolower($_POST["username"]) : false;
$message = !empty($_POST["message"]) ? $_POST["message"] : false;
$sticky = false;
if ($username === false) {
	$botMessage = "Who are you?";
} else if ($message === false) {
	$botMessage = "Please write something before hitting send.";
} else {
	$json = json_decode(file_get_contents("https://catfact.ninja/fact?max_length=1000"), true);
	$botMessage = $json["fact"];
}
$outputArray = [
	"message" => $botMessage,
	"sticky" => $sticky
];
echo json_encode($outputArray);
?>