Cross origin requests are only supported for protocol schemes: http, data,
chrome, chrome-extension, https.

<?php

$servername = "localhost";
$username = "bioManager";
$password = "@manager@bioDB";
$dbname = "biodb";

// Cria conexão
$conn = new mysqli($servername, $username, $password, $dbname);
// Verifica conexão
if ($conn->connect_error) {
    die("Erro de conexão: " . $conn->connect_error);
}

$result = mysqli_query($conn, "SELECT * FROM dominios");

$dados = array();

if ($result->num_rows > 0) {

    while($row = $result->fetch_assoc()) {
        $row = array_map('utf8_encode', $row);
        array_push($dados, $row);
    }

    echo json_encode($dados);

}

$conn->close();
?>

function carregaDominios(){
    $.ajax({
         method: "POST",
         url: "../PHP/carregaDominios.php",
         success: function(result){
              alert(result);
         }
    });
}