I have an issue reported here https://github.com/jenstornell/kirby-panel-flags/issues/1
It’s clear that from the image the domain name is missing:
The code that make this is:
$url = u() . '/assets/plugins/kirby-panel-flags/icons/' . $filename . '.svg'
u() give the installation url, like:
(I know that I should probably use
kirby()->urls()->assets() for it in this case)