This extension has stopped being useful. Airtable made changes to their API that prevent attachment URLs from working after a few hours. Check this article for more information.
When you try to get the URL of an attachment on Airtable, it will also include the file name. Use this tool to extract only the URLs of the attachments without their file names. It works with single or multiple attachments. All URLs will be stored in their assigned field. If you have multiple attachments in a single record, the URLs will be comma separated.