I recently answered a question about simple-scan unable to detect a scanner, and it turned out to be a snap-only bug (possibly a permission issue).
An Ask Ubuntu user suggested informing the snap packager of the issue.
It turns out that the packager is canonical (https://snapcraft.io/simple-scan), and there is no link to report an issue on this page.
I saw this question, but snap info simple-scan reverts me back to https://snapcraft.io/simple-scan, which does not have a bug reporting link.
And it would not be fruitful to report the bug at the simple-scan development site because they did not package it.
How to report a bug for such snap packages? It is most likely not a snapd bug, but a packaging issue.