Output image with my size

I cant get to image with my own size that I have registered.
I am using an example from here:

$cmb->add_field( array(
	'name'    => 'Test File',
	'desc'    => 'Upload an image or enter an URL.',
	'id'      => 'wiki_test_image',
	'type'    => 'file',
	// Optional:
	'options' => array(
		'url' => false, // Hide the text input for the url
	),
	'text'    => array(
		'add_upload_file_text' => 'Add File' // Change upload button text. Default: "Add or Upload File"
	),
	// query_args are passed to wp.media's library query.
	'query_args' => array(
		'type' => 'application/pdf', // Make library only display PDFs.
		// Or only allow gif, jpg, or png images
		// 'type' => array(
		// 	'image/gif',
		// 	'image/jpeg',
		// 	'image/png',
		// ),
	),
	'preview_size' => 'large', // Image size to use when previewing in the admin.
) );

link: https://github.com/CMB2/CMB2/wiki/Field-Types#file

$image = wp_get_attachment_image( get_post_meta( get_the_ID(), 'wiki_test_image_id', 1 ), 'my-size' );

but when i try to output the image (echo $image) i don’t get nothing.
var_dump($image); deduces: string(0) “”

Need help.

• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.
• This topic was modified 3 years, 11 months ago by theme2021.