If it was just one occurrence then maybe a large fine or some community service. If someone does it multiple times then maybe prison time. I’m just guessing really. People who are more knowledgeable about the justice system than I am could probably answer this better.
I live in the UK and we already have hate speech laws making certain speech illegal, e.g. extreme racist speech. Maybe it wouldn’t be so bad if the encouragement of suicide was also illegal under such laws. Do we really think that people should have the right to encourage suicide? Surely the right of others to live is more important.
I dunno, I’m just suggesting it, I’m not saying the law should definitely be changed in this way.