Why I cant download my mobile legends

What happens when you try? Do you get an error? If so what does it say exactly?

If its asking you to verify your payment method, then you must do so before you can download anything from the App Store. Even if it's free. If the payment method you had stopped being verified or this is a new account that's never had a payment method, then you need add one that can be verified.

Link-> Change, add, or remove Apple ID payment methods - Apple Support