REST public POST giving 403 forbidden nginx

I have created public rest endpoint with POST method and when I try ajax or use insomnia always response with 403 forbidden nginx. Why isn’t this working and how could I resolve my problem?

Route:

add_action('rest_api_init', 'registerContactPOST');

function registerContactPOST(){
    register_rest_route('fb/v1', 'contact',
        array(
            'methods' => 'POST',
            'callback' => 'contactPOST',
            'permission_callback' => '__return_true'
        )
    );
}

function contactPOST($requestData){
    return 'ok';
}

Client ajax:

<script>
    jQuery.ajax( {
        url: '/wp-json/fb/v1/contact',
        method: 'POST',
        data:{
            'xyz' : 'xyz'
        }
    } ).done( function ( response ) {
        console.log( response );
    } );
</script>

In xampp localhost it works fine but not with remote server.