WhatsApp Business not working for non-iphone users

Somehow my shortcut returns errors when it needs to send a message via whatsapp for business to non-iphone users, saying the receiver hasn’t turned imessage on. Why? iMessage isn’t even in the shortcut??

Do you know why and how to fix it?

Always worth a search first. This one’s in the top three when you search for “WhatsApp”, and intros as something that looks like your question.