error (10413) occurs when checking out

This is my first time to build a store with zen-cart.

I installed the payment module "Paypal Express Checkout" (other payment modules removed) and set it up with my paypal account A.

Now I'm testing the checkout.
After I made the payment with another paypal account B (different from the paypal account A, which is used to receive money), it goes back to my store and prompts:

10413 Transaction refused because of an invalid argument. See additional error messages for details. - The totals of the cart item amounts do not match order amounts.
:shocking:

I try to provide more info regarding this test:

Before above attempt, I created two testing products, one was priced $0.01, another was priced $0.02.
I made two tests, one was buying one of the two products, another was buying both of the two products.

Can anybody help me out?
Thanks!

If you search the forums for 10413, you'll find plenty of threads that deal with this issue - I'm sure there's an answer in there for you.