Unfortunately the Slack invite link onhttps://firecracker-microvm.github.io/ is no longer valid and needs to be replaced:

Fwiw, if you want to get alerted once a link expires you can set up a health check via

curl -sLH'user-agent: Chrome/999''the-invite-url'| grep -o'isSharedInviteError":false'

The health check fails if the command returns an empty string (also, the user agent is important). I would recommend to set up a redirect rule from a static URL so that you can update the link without having to change the website or any monitors.