Insufficient fund in stripe account

\Stripe\Stripe::setApiKey("sk_test_vKA2W1UsnAfPfDsA1dfdK04n3dfr6");

\Stripe\Charge::create(array(
    'currency' => 'USD',
    'amount'   => 10000,
    'card'     => 4000000000000077
));

You can use this code and add balance for make transfer operation for your test account.

You can do one more thing to add funds to your test account.

Just login into your stripe account and go to Payments and click on Create your first payment or new payment button.
When you click on it you can see a popup window that opens, here you can fill your amount.
Just remember to use card number: 4000000000000077
and click on Create payment button.

Your payment will be added directly (bypassing the pending state) and you can make transfers with your stripe testing account.

If you are getting Insufficient funds error then you can use the below card number to transfer the payment in Test mode. Card Number : 4000000000000077

Your Stripe account only has a HKD bank account, and thus it only has a HKD balance. You can't create transfers in USD because your account doesn't have a USD balance.

In order for your account to have a USD balance, you'd need to link a USD bank account to it. However, at this time, HK Stripe accounts can only have HKD bank accounts, as noted here.