WhatsApp uses SMS to send text messages, and because the iPad only supports iMessage and similar text messaging apps rather than SMS, WhatsApp simply won't run on the iPad.
WhatsApp na-eji SMS zipu ozi ederede, na n'ihi na iPad naanị na-akwado iMessage na ngwa ngwa ozi ederede kama SMS, WhatsApp naanị agaghị agba ọsọ na iPad.