Mattermost transport, showing "The mattermost-icon format is invalid." for icon "πŸ‘»"

Trying to use mattermost transport and change icon to existing emoji β€œ:ghost:” shows β€œThe mattermost-icon format is invalid.”
There is nothing that makes it clear that it has to be an url.
This field should also allow for emoji icon names (or another field for the emoji variant)

By forcing me to enter a URL (or leave it empty) I figured I should use the LibreNMS logo, so in the end I used:, maybe that should be the default instead :wink: