Get into Basic Configuration menu from Azure Marketplace VM

I need to enable Webconf, but can’t for the life of me get (back) into the basic configuration menu.

I run a Azure Marketplace edition of CheckMK, but anything I try (hit F1 in serial console or from SSH) doesn’t work. I tried finding some info on log files where these settings are set, but cannot find this information. That is basically where my knowledge ends.

How can I enable Webconf from the command line? It shouldn’t be that difficult I assume.

Any help is appreciated.