Payment instrument type is not accepted by this merchant account

[xjd001]

Hi,

I want to have my website able to accept credit card payments,

and I get a access_token from PayPal Dev center, which is under the "Express Checkout via Braintree SDK - Live Account" section,

and it's able to connect braintree by using this access_token,

but cannot create transactions, raising error: "Payment instrument type is not accepted by this merchant account",

which step do I miss?

Can anyone help?

Thx.