Hello Stanely,
Comments of Posts, Pages or Image Attachments can be controlled via WordPress core feature.
Following articles will be helpful to you.
https://en.support.wordpress.com/enable-disable-comments/
https://en.support.wordpress.com/screen-options/
Quick Tip:
1. Make sure “Discussion” is checked in the Screen Options of a Post, Page or Attachment
2. When the “Discussion” will be checked you will find “Allow Comments” and “Allow Trackbacks” checkboxes under the editor
3. You can enable/disable comments here.
In order to access Attachment (image) details, Please follow the simple steps.
– Go to `Media > Library`
– Click on any image, you wish to edit details
– Click on Edit more details
– Here you will find again, Screen Options and Comments control under the editor.
Quick access to Attachment iamge
– Make sure you are logged-in
– Open image you wish to edit, in the browser
– You will find Edit link under the Post, Page or Attachment image
– Click on Edit and you will be on the same screen as explained above.
Thanks