MB Blocks - Custom Field doesnt render in Gutenberg

I´ve mad a simple Block with one custom field (text). I´ve followed the tutorial, but in Gutenberg the custom field doesnt shows up in Gutenberg.
https://ibb.co/dLVHbZr
https://ibb.co/JxNyH7M
https://ibb.co/C1kSw4B

Here are the codes:

<?php
add_filter( 'rwmb_meta_boxes', 'your_prefix_function_name' );

function your_prefix_function_name( $meta_boxes ) {
    $prefix = '';

    $meta_boxes[] = [
        'title'       => __( 'zweier', 'your-text-domain' ),
        'id'          => 'zweier',
        'icon'        => [
            'background' => '',
            'foreground' => '#dd3333',
            'src'        => 'airplane',
        ],
        'category'    => 'oxygen-vsb-blocks',
        'supports'    => [
            'align' => [''],
        ],
        'render_code' => '{{ post_id }}
<div class="zweierText">Hier sollte eine Textzeile sein:{{ zweierText }}</div>
',
        'type'        => 'block',
        'context'     => 'content',
        'fields'      => [
            [
                'name' => __( 'Text', 'your-text-domain' ),
                'id'   => $prefix . 'zweierText',
                'type' => 'text',
                'size' => 12,
            ],
        ],
    ];

    return $meta_boxes;
}

Render Code:

{{ post_id }}
<div class="zweierText">Hier sollte eine Textzeile sein:{{ zweierText }}</div>

The Post ID renders, as well as the content of the div - expect the {{ zweierText }}