You can start a conversation with any WhatsApp number by opening the url wa.me/number. The number must include the country prefix. There are also some apps and

You can start a conversation with any WhatsApp number by opening the url wa.me/number. The number must include the country prefix. There are also some apps and webpages that helps with this process (Disclaimer: I'm the author of one of them for Android [0]) [0] https://play.google.com/store/apps/details?id=com.trianguloy.openInWhatsapp https://play.google.com/store/apps/details?id=com.trianguloy...