我如何获得一个访问令牌贝宝休息api -实时服务器

根据PayPal开发者文档，在进行REST调用时，我需要提供'访问令牌'，我无法在我的PayPal帐户中的PayPal控制面板内找到。

curl -v https://api.sandbox.paypal.com/v1/payments/payment '
  -H "Content-Type:application/json" '
  -H "Authorization: Bearer Access-Token" '
  -d '{
  "intent": "sale",
  "payer":
  {
    "payment_method": "credit_card",
    "funding_instruments": [
    {
      "credit_card":
      {
        "number": "4012888888881881",
        "type": "mastercard",
        "expire_month": 12,
        "expire_year": 2018,
        "cvv2": 111,
        "first_name": "Betsy",
        "last_name": "Buyer"
      }
    }]
  },
  "transactions": [
  {
    "amount":
    {
      "total": "7.47",
      "currency": "USD"
    },
    "description": "This is the payment transaction description."
  }]
}'

我如何获得一个在线(不是沙盒)PayPal帐户的"访问令牌"?