Multiple File upload Ajax set to true

Hi!
I created a field for uploading file with multiple checkbox checked.
I want to have the behaviour as the upload file field when it’s uploading a single image (to have a preview of it).
As far as I figured out, it must have ajax set to true, so I created manually and set the ajax to true. Now what I want happens but the meta field is never saved.
When I echo the meta with “foreach” to ‘content-single-resume.php’ it gives me empty items.

Can you please help me?

https://wordpress.org/plugins/wp-job-manager/