curl --request POST \
  --url https://api-m.sandbox.paypal.com/v1/commerce/billing/wallets/{wallet_id}/wallet-transactions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "type": "TOPUP",
  "paid_credits": "20.0",
  "credits_to_void": "20.0",
  "granted_credits": "10.0",
  "metadata": [
    {
      "key": "reason",
      "value": "balance depleted"
    }
  ]
}
'

{
  "wallet_transactions": [
    {
      "wallet_transaction_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
      "wallet_id": "1a901a90-1a90-1a90-1a90-1a901a901a90",
      "payment_status": "SETTLED",
      "source": "MANUAL",
      "transaction_status": "PURCHASED",
      "transaction_type": "INBOUND",
      "amount": {
        "value": 120.35,
        "currency_code": "USD"
      },
      "credits": "100.0",
      "settled_at": "2022-04-29T08:59:51Z",
      "failed_at": "2022-04-29T08:59:51Z",
      "created_at": "2022-04-29T08:59:51Z",
      "metadata": [
        {
          "key": "reason",
          "value": "balance depleted"
        }
      ]
    }
  ],
  "meta": {
    "total_count": 123,
    "total_pages": 123,
    "current_page": 123,
    "next_page": 3,
    "prev_page": 1
  }
}