从标头中获取授权令牌

I have been working on web services with wordpress and I hit Authorization token header from postman but enable to get that in php code. Here is my code.

$reuqest_token = getallheaders();

And here is my .htaccess file

# BEGIN WordPress
<IfModule mod_rewrite.c>
 RewriteEngine On
 RewriteBase /
 RewriteRule ^index\.php$ - [L]
 RewriteCond %{REQUEST_FILENAME} !-f
 RewriteCond %{REQUEST_FILENAME} !-d
 RewriteRule . /index.php [L]
 RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
</IfModule>
# END WordPress

Please anybody let me know if there is any another alternative.