FusionHub SSL Certificate enable


I need help how to enable my SSL key for my fusion-hub cloud appliance.

I purchased 1 cheap PositiveSSL from www.ssls.com and they only provided me 1 private key file but no public key.

The www.ssls.com provided instructions on how to use their ssl key for “webhost” but for my understanding fusion-hub is an appliance is not a website.
LINK = https://www.ssls.com/knowledgebase/how-can-i-complete-the-domain-control-validation-for-my-ssl-certificate/