The error you are seeing is a result of the file not being publically accessible. What I mean is that the URL you shared in the post requires you log into Trello in order to access the file. Your Zap needs to be able to access the file from Trello without having to log in.
You may be using a Trello trigger which supplies the actual file object. When you are setting up your Google Drive step, you can look for a field coming in from Trello which is the attachment and says (exists but not shown). If you use this field then your Google Drive step should work.
If you try this and are still having issues I would encourage you to reach out to Zapier Support when logged in using our contact form (https://zapier.com/app/get-help). We would be more than happy to continue working with you to find a solution to your problem.
Ted - Zapier Support