Prepare a user operation

curl --request POST \
  --url https://api.cdp.coinbase.com/platform/v2/evm/smart-accounts/{address}/user-operations \
  --header 'Content-Type: application/json' \
  --data '{
  "network": "base-sepolia",
  "calls": [
    {
      "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
      "value": "0",
      "data": "0xa9059cbb000000000000000000000000fc807d1be4997e5c7b33e4d8d57e60c5b0f02b1a0000000000000000000000000000000000000000000000000000000000000064"
    }
  ],
  "paymasterUrl": "https://api.developer.coinbase.com/rpc/v1/base/<token>"
}'

{
  "network": "base-sepolia",
  "userOpHash": "0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef",
  "calls": [
    {
      "to": "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48",
      "value": "0",
      "data": "0xa9059cbb000000000000000000000000fc807d1be4997e5c7b33e4d8d57e60c5b0f02b1a0000000000000000000000000000000000000000000000000000000000000064"
    },
    {
      "to": "0xdac17f958d2ee523a2206206994597c13d831ec7",
      "value": "1000000000000000",
      "data": "0x"
    }
  ],
  "status": "pending",
  "transactionHash": "0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
}