How can I help my brother?

I got the news today and I want help because I don't understand this disorder. My brother was just diagnosed and my family refuses to support him. He may come stay with me in my city.

He's always had some issues with motivation, and I want to see him make the best of this opportunity and support him any way I can (our parents were neglectful and never treated his mental health issues, even though it was clear he was struggling from a young age).

He's an adult so I don't want to make him do anything, but I do want there to be conditions for him to stay with me, like seeing a psychologist, staying medicated, going to school, doing chores, etc. I am willing to cover costs for rent, food, psych, etc. until he can get on his feet.

How can I best support him?