从联系表单7获取自定义字段值时出现问题

I have trouble when I used this code below to get value form custom field of post type = post

[dynamichidden chapter "CF7_get_post_var key='file_download'"]

[dynamichidden dynamichidden-508 "CF7_get_custom_field key='file_download'"]

In the picture below, I set return value is File URL

http://prntscr.com/ngjrpn

So I got email with ID value. How can I get URL value of this case. Thanks a lot.

Please use this contact form 7 extension

https://wordpress.org/plugins/contact-form-7-dynamic-text-extension/

This extension provide easly way get the value:--

(i). [CF7_GET key=’value1’]

(ii). [dynamictext dynamicname “CF7_POST key=’value2'”]