How to offline activation license on Metabase

I want to know if metabase's service provides offline activation license? because my metabase's service is installed in an offline environment.

If I use white IP to ensure access to token-check.metabase.com to verify your license ,Do I have to open the firewall to stay connected?

Only in the enterprise version, please contact us to help at metabase dot com

Thanks.

Should I contact you by email or this discussion forum?

email: help at metabase dot com