What's the best way to encourage someone to call when they're showing outward signs of depression but you don't know them? I saw someone who was very clearly d

What's the best way to encourage someone to call when they're showing outward signs of depression but you don't know them? I saw someone who was very clearly depressed streaming the other day. They weren't responding to chat. Crying. Fetal position on the floor for 7+ hours. Very depressing social media posts, etc. But I did not know this person. I did encourage them to call, however it was a difficult message to compose. You don't want to make them feel like they're a burden or weak ("call if you need someone") and some people may need encouragement to actually pick up the phone. So in a situation with a stranger online, who may not see or respond to your message, what would you say?