curl --request POST \
  --url https://api.prime.coinbase.com/v1/portfolios/{portfolio_id}/staking/initiate \
  --header 'Content-Type: application/json' \
  --data '{
  "idempotency_key": "<string>",
  "currency_symbol": "<string>",
  "amount": "<string>",
  "metadata": {
    "external_id": "<string>"
  }
}'

{
  "activity_id": "<string>",
  "transaction_id": "<string>"
}