Registering MD financed car with co owner

Hello, I just moved to DC from MD and i'm confused on the process of registering my car. My dad is a co owner but doesn't drive my car but its currently being financed. I have the lien as well.

How do I register my car with the DMV while its being financed? Does my dad have to sign the lien somewhere? Or do I have to call my financing company to send it? Thanks!