How to fix broken Laravel link to local file system?

We inherited a custom laravel app and in the admin area, a link that points to a file in the local storage has broken:

This site can’t be reached
The webpage at https://domain.tld/admin/donor/1818/document/56/DCCA8ACC-7B1B-4D90-977C-257BDA5AE56E.png might be temporarily down or it may have moved permanently to a new web address.
ERR_INVALID_RESPONSE

These links used to work, so I'm not sure what broke. I've verified that the all folders and files in the app have correct permissions and ownership.

via Chebli Mohamed