You must use the raw image file on Imgur in order to get the full URL privatization of the Imgur image.
Right-click on the image on Imgur.
Click on "copy image address"
Copy your link from your Playlist or Song into the form on https://mintgate.app & Select the token type you wanna gate your content with. Then Select the Token and needed Amount Click Generate Link and you will get a link to share. The content will also be posted to the Token Profile. You can share your new TPP link anywhere and it will only be accessible for token holders