I am confused, I thought for Ghost you have to set up comments yourself as well: https://www.ghostforbeginners.com/how-to-enable-comments-on-...
I have been running Ghost for free on OpenShift but haven't set up comments. I would recommend it but I don't think OpenShift are taking on new accounts for the v2 platform where Ghost is available -- they are transitioning to "next gen" and I haven't checked if they have Ghost on that.