How to help a sibling who is not motivated in life

I have a younger brother who just...doesn't really seem to be motivated to do much of anything in life. I want to help him, but at this point I'm not sure how.

He's 22. He lives with my dad, has never had a long term job (he had one seasonal job last year but that's it), and only completed 1 year of college. He says he applies to jobs but it doesn't sound like he's very consistent. He spends most of his time online or playing video games. Doesn't go out at all with friends, doesn't seem interested in relationships. When I ask him what he wants to do with his life or what his goals are, his response is just "I don't know."

My sister and I (also older than him), are pretty accomplished. We completed college and have full time jobs. I've lived on my own since I was 22 and now I'm married and live in a nice house. Sister also lives with our dad because of the high cost of living but she's independent and takes care of herself. My parents divorced when we were young and I think they coddled my brother and didn't place as high expectations on him as they did us. I think he needed more guidance and structure which was not given growing up and now this is the consequence.

They complain to me that he doesn't seem motivated to do more with his life and I've tried to help by encouraging him to keep applying for jobs and continue community college, trying to get him to think about goals and starting productive daily routines. I've recommended that they get him into therapy, but my parents are not the type that are super open to therapy so I don't know how to approach getting him help. I live nearly an hour away from my dad so I can't be over there all the time monitoring what my brother does, which makes it hard to help. It's also hard to help when I try to approach these topics with him and the best I can get out of him is "I don't know" or silence.

So, I don't know. I want to help because I care about him and I know he can do better. But what do you do with someone who doesn't have any drive to better themselves in life or even take care of themselves?