PHP - How to get and set Bearer Token

bearer-token.php

<?php
/** 
 * Get hearder Authorization
 * */
function getAuthorizationHeader(){
        $headers = null;
        if (isset($_SERVER['Authorization'])) {
            $headers = trim($_SERVER["Authorization"]);
        }
        else if (isset($_SERVER['HTTP_AUTHORIZATION'])) { //Nginx or fast CGI
            $headers = trim($_SERVER["HTTP_AUTHORIZATION"]);
        } elseif (function_exists('apache_request_headers')) {
            $requestHeaders = apache_request_headers();
            // Server-side fix for bug in old Android versions (a nice side-effect of this fix means we don't care about capitalization for Authorization)
            $requestHeaders = array_combine(array_map('ucwords', array_keys($requestHeaders)), array_values($requestHeaders));
            //print_r($requestHeaders);
            if (isset($requestHeaders['Authorization'])) {
                $headers = trim($requestHeaders['Authorization']);
            }
        }
        return $headers;
    }
/**
 * get access token from header
 * */
function getBearerToken() {
    $headers = $this->getAuthorizationHeader();
    // HEADER: Get the access token from the header
    if (!empty($headers)) {
        if (preg_match('/Bearer\s(\S+)/', $headers, $matches)) {
            return $matches[1];
        }
    }
    return null;
}