Yeah. The main way most people can support someone in that situation is by letting them know that you’re there for them and helping them get assistance from an external professional. Even trained professionals aren’t supposed to work with people they know if possible. Getting them to talk with someone who has distance is important. All you should do is listen without offering advice and making sure they feel cared about.
You’re not responsible for them. Unless they are in the middle of an active attempt, all you should do is encourage them to seek help or help them get help. That’s the only conceivable time anything resembling negotiations should ever happen, and even then, you want to hand them off to experienced professionals as soon as possible.
Outside of suicidality, it’s important to not give advice outside of what’s asked for. It’s useful to talk in respect to your own experiences and not make universal claims about what works for you personally.