Unable to complete my Apple Account to update WhatsApp

Hi

have being asked to contact iTunes support

just open my iCloud but it’s not working

I wanted to update my WhatsApp but it said I can’t that I have to sign in on iTunes or something

i want to complete my iD Apple but I can’t because I don’t have a Mastercard

I tapped on none but it says I should contact iTunes support

[Re-Titled by Moderator]