Hebrew text MySQL utf-8 in database mysqli connection php web and Ionic2 app html pages

I have mysqli back-end connection.php file for Ionic2 application:

<?php
header("Access-Control-Allow-Origin: *");

$con = mysqli_connect('localhost', 'user', 'password');

if (!$con)
{
    echo 'Not Connected To Server';
}

if (!mysqli_select_db ($con, 'database'))
{
    echo 'Database Not Selected';
}
?>

and another one inside html page to display table content in web:

<?php
include 'connect.php';
$sql = "SELECT * FROM  table";
$result = $conn->query($sql);
?>

with own connect.php:

<?php
$servername = "localhost";
$username = "user";
$password = "password";
$db = "database";

$conn = new mysqli($servername, $username, $password, $db);
if(!$conn)
{
    die ("Error on the Connection" . $conn->connect_error);
}
?>

both from same MySQL database table:

id | hebrew_name | english_name 
--------------------------------
1  | עפולה       | Mizra
2  | צפת         | Mahanayim

in both cases Hebrew text appears as question marks as in html page:

id | hebrew_name | english_name 
--------------------------------
1  | ??????       | Mizra
2  | ??????       | Mahanayim

and same result in Ionic2 application lists ??????

for web html file I have tried to add:

<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />

this way:

<!DOCTYPE html>
<html>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8' />
<body> 
...

but I got same result, and I'm not sure, how to set it for mysqli connection.php itself or any other php file, which uses this connection.php for example:

<?php
require 'connection.php';

$id = mysqli_real_escape_string($con, $_POST["id"]);

$sql = "SELECT hebrew_name, english_name FROM table where id='".$id."'";
...
?>