link I wrote that a few years il y a out of a lot of personal experience and felt it was important to put out there. Presently and with professional Mental Health First Aid training and what not, I still say that general routine and steps to handling someone who is actively suicidal is still very good.
The topic really isn't an easy one to handle and saying "you should live" really doesn't help since I'm pretty sure they would be happy and find a reason to live if they could just magically do that and I'm sure they've heard it plenty enough that toi should never kill yourself.
Honestly the main thing when it comes to anyone who is actively suicidal is to keep them talking and not acting, comfort and support them, keep an eye out for them and stay with them until they are safe. It is also important to always try to at least bring up and direct them to proper professional help since as much of a good friend toi might be, it isn't your place and toi aren't capable ou trained to take on everyone else's mental health.
Ideally, if toi could question them and get plus information on why they are feeling that way and discuss with them in an understanding, nonjudgemental, and caring way what they are feeling and COMPASSIONATELY rationalize and try to find certain things they can attach to in the world to give them SOME reason to live, then toi should try to do that
But I would recommend being careful about it as digging into it can be a bit risky if toi aren't prepared.
So if I had to say anything it would be to ask what makes them feel that way and if anything in particular happened to make them feel that way in the immediate.