Braintreepayment：商家未设立接受PayPal

I am just going through the Braintreepayments "Get Started" page. This is a very simple tutorial. A few lines of code in both client and server, in my case Android and PHP. Basically, my codes are same as per tutorial.

I am getting unexpected exception thrown as following.

com.braintreepayments.api.exceptions.UnexpectedException: Merchant is not setup to accept PayPal

In the control panel, PayPal is enabled by default in the Sandbox.

But I could not find the place to enter Paypal Sandbox Merchant Account as explained in this doc. Probably, this document does not cover for sandbox.

Can anyone please point me out if there is any steps or doc I missed out to check?

After Braintree support team has enabled the Paypal as a processor connection for my sandbox, I am able to continue the to make the payment with Paypal.

I sent further question, why Paypal is not default enabled as a processor connection in my Sandbox. Below is support team reply.

I was wondering how to join Paypal sandbox accounts in Braintree. According to Braintree support team reply, this is not possible. Braintree is a separate and an entirely enclosed environment.

@Sithu Your sandbox was created outside supported country, which is not a supported country with PayPal that's why you are getting error "Merchant is not set up to accept PayPal".

Example:
If you are a developer working for a US based merchant on an integration, you will need to signup as a US based braintree sandbox account. You can do this on BrainTree website by selecting United States as your country using the drop-down menu on the bottom left of the page.

Remember: bottom left of signup page >> Select Country as US

I signed up for another sandbox account on BrainTree using US as my country and it worked perfectly.

After signup, got to Settings >> Processing and check "Accepted Payment Methods" list, you will see a "paypal" icon there that's means your account support paypal payment method.