Installing WhatsApp

i recently got a new phone, I switched from an android to this iPhone and I’m trying to install WhatsApp (even though I allowed the phone to transfer WhatsApp files from my android) and it’s saying I need to choose a purchase method, so I just clicked phone number instead and then it says I have to contact a server because this phone hasn’t been used to purchase before

i just want to install WhatsApp without purchasing or putting in any card details ????