Openvas-nasl with private key

Does anyone out there know if there is a way to use SSH keys with openvas-nasl? I know of the construct

openvas-nasl ... --kb="Secret/SSH/login=<username>" --kb="Secret/SSH/password=<password>"

but I’m not sure how to use it with a private key.

A broader (but perhaps ignorant) question is, is there any guide to coming up with dependency and kb arguments to openvas-nasl? I know I can run openvas-nasl --help, but it does not offer any guidance at this depth.

Thanks in advance!