Depression has a way of putting the very thing that would help just out of reach. Getting dressed, ringing a clinic, sitting in a waiting room. If you have been meaning to sort something out for months and it keeps sliding to next week, that is the low mood doing what low mood does.
Online therapy means talking to a qualified therapist by secure video from wherever you feel comfortable, with no commute and no waiting room. It suits a lot of people. It does not suit everyone, and the right option depends on how you are doing and how safe you are right now. Worth being honest about that before you book anything.