Send the following on WhatsApp
Continue to ChatSaying "السلام عليكم" to an unknown caller on the telephone https://www.fatwa-online.com/saying-%d8%a7%d9%84%d8%b3%d9%84%d8%a7%d9%85-%d8%b9%d9%84%d9%8a%d9%83%d9%85-to-an-unknown-caller-on-the-telephone/