title: PayPal sandbox Merchand id
body: <p>Where can I find the MerchantId in a PayPal Sandbox for a Business account?</p>
  
  <p>I need it to fill the merchant_id property for a Payee object (a third party who will receive part of a payment via credit card), which is then added to a Transaction.
  I use the .NET SDK but it doesn't matter in this case.</p>