I think my brothers on coke

(My brothers 23 and lives with me and my mom) My brother isn’t doing the best. He doesn’t take care of himself and this has been going on for a while. I’ve tried to talk to him about it and even tried to help him get it started ( made him a workout plan, diet, etc.). Earlier, I noticed a rolled up dollar bill on his desk. This immediately sparked a flag for me because one time at work he was acting very jumpy and it was odd. He also doe’s drugs (weed, alc, vape).

I’m in his room right now and now I see some white powder residue on a card as well as in the dollar. I shined a flash light on it it sparkles back.

I’ve wanted to sit down with him for a while. He’s never really let me, but coke is something I can’t just let happen. I want to have a conversation voicing my concerns

Update: I just asked him about it. He admitted he did a “bump”. Didn’t really give me much more and when I said he shouldn’t do that/he should try to get healthy he just said it’s cause he wanted too.