if anyone try to pay using my hosting's whmcs billing script its always ask verified paypal how to stop asking card verified . i want to user can pay using unverfied paypal also.
You need to contact developer who has experience with PayPal API to set that up for you. I wouldn't advise allowing customers to pay without a verified PP account though that's just me & my $0.02. They can pay for whatever they're purchasing from your site through PayPal even if they don't have an account with PayPal. Have the developer look at how your PayPal API is configured for your shopping cart.
Just put a credit card on your PP account, some sites have to do that they won't remove it because of one person...