Yep It does not work though here is log I captured while testing it under ubuntu 16.04 should help.
= Seccomp =
Time: Feb 13 09:44:18
Log: auid=4294967295 uid=1000 gid=1000 ses=4294967295 pid=17899 comm="notepadqq-bin" exe="/snap/notepadqq/43/usr/local/lib/notepadqq/notepadqq-bin" sig=31 arch=c000003e 50(listen) compat=0 ip=0x7f51ca117217 code=0x0
* add one of 'browser-support, desktop-legacy, libvirt, network-bind' to 'plugs'
Also app icon is not showing and this should be fixed by adding full path to the icon file.
I had these on AppImage of notepadqq should be harmless.
Thanks for creating snap.