How do I make an object in Google Cloud Storage accessible via a link but require a key or some other form of verification to access it?

I am creating an application that requires a file to be retrived from a Google Cloud Storage bucket. Right now, I have the file's public access set to true so I can access it via URL.

Is it possible to still access the file via URL, but require some sort of authentication in the form of a key etc.?

I have looked through how IAM permissions work; however, I am not confident in my ability to use such tools proficiently yet.

You can't set a permission on a single object on Cloud Storage. The correct way to achieve that is to have a service, that check the permission of the user and the right to access the object.

If the user can access it and want to download it, you can generate a signed URL and send it to the user. With this URL, the user can download the file in a secure way (the bucket is not public and only the Signed URL can access the file, for a limited period of time)

That's not currently available.

One possible workaround would be to write your own small service that accepts whatever custom authorization or keys you like and then vends a short-lived signed URL as a redirection. So the user would send GET to https://yourservice.com/download?magicKey=12345, and then your service would evaluate it and maybe reply with a 304 to https://storage.googleapis.com/yourbucket/yourobject?elaborateSignedUrl, with the signed URL limited to just a minute or two of validity. This would solve your problem but would require writing and maintaining the URL vending service.