You must use the Publish to the Web feature in Google Forms in order to get the full URL privatization of the Google Forms.
Go to the Google Forms.
Go to the Navigation bar.
Click on Publish to the Web.
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