REST API Update field

Hello guys,

I have a question according to the REST API for updating a cmb2 field value.

This is the code for the registration of he field and the box:

$cmb = new_cmb2_box(
			array(
				'id'           => 'hd-object-viewer-mb',
				'title'        => __( '3D View Scene', 'hd-3d-viewer' ),
				'object_types' => array( 'hd-object-viewer' ),
				'context'      => 'normal',
				'priority'     => 'high',
				'show_names'   => true,
				'show_in_rest' => true
			)
		);

		$cmb->add_field(
			array(
				'name' => 'Test Text Area',
				'desc' => 'This is the json data',
				'id'   => 'hd-object-viewer-mb-scene-json',
				'type' => 'textarea',
				'sanitization_cb' => false,
				'escape_cb'			=> false,
			)
		);

I registerd my CPT like this:

register_post_type(
			'hd-object-viewer',
			array(
				'label'               => __( '3D View', 'hd-3d-viewer' ),
				'description'         => 'Recipe custom post type.',
				'public'              => true,
				'exclude_from_search' => true,
				'show_in_rest' => true,
				'supports'            => array( 'title' ),
				'menu_icon'           => 'dashicons-admin-site',
			)
		);

I now want to update the field via the REST API. When i make a GET Request to /wp-json/cmb2/v1/boxes/hd-object-viewer-mb/fields/hd-object-viewer-mb-scene-json i get the field back (so the field is registered in the API)

But when i do a POST request to the same URL i get an error:

{
    "code": "cmb2_rest_no_field_by_id_error",
    "message": "No field found by that id.",
    "data": {
        "status": 403
    }
}

My POST body is:

{
    "object_id": 49,
    "value": "other value test",
    "object_type": "post"
}

I also tried it with the “hd-object-viewer” (CPT) object_type which results in the same error.

What is the object_id anyways. I considered it as the post id, maybe this is not correct.

For Authentication i used a Application password with my admin User, so i am pretty sure i am authenticated at it would say otherwise. Maybe i don’t have the permission to change the metafield, which would be weird as this is the application password for the admin user.

Any help would be appreciated.

Thanks in Advance.