Scanning Firewalls with Credentials other than SSH

What’s a good way other than SSH to credentials scan your Firewalls using InsightVM?
If SSH is disabled on your firewalls, what other method would you recommend? Is InsightVM able to credential scan vi a web/gui interface?

SNMP can be used, though it will likely receive a fingerprint of <1.
SSH is vastly preferred, however. It will provide a fingerprint of 1.
If you look at the UNIX and related targets documentation, it describes the commands that are required to be run when fingerprinting.