Yahoo Finance Institutional holdings API

Please help me write a data collection script with the EveryInfra Yahoo Finance Institutional holdings endpoint (yahoo_finance/institutional_holdings).

How the endpoint works:
- Request: POST https://api.everyinfra.com/api/v1/social with the header Authorization: Bearer <API key>. Read the key from the EVERYINFRA_API_KEY environment variable and never hard-code it.
- In the request body, set platform to yahoo_finance and action to institutional_holdings, and put the parameters inside params.
- Required parameters:
  - keyword: One US-listed ticker, such as NVDA or BRK.B; a leading $ is removed. Pass one symbol, not a company name or a list. Only US-listed tickers are covered.
- Returns one object. Main fields: symbol, institutional_ownership_pct, shares_outstanding, holdings_value_usd, holders, shares_held, increased_holders, increased_shares, decreased_holders, decreased_shares, unchanged_holders, unchanged_shares; 17 fields in total, full list at https://api.everyinfra.com/api/v1/social/catalog?platform=yahoo_finance.
- Example request body:
{
  "platform": "yahoo_finance",
  "action": "institutional_holdings",
  "params": {
    "keyword": "AAPL"
  }
}
- Price: $8 per 1,000 requests; failed and empty results are not charged.
- For dozens or hundreds of targets, add "mode": "async" to the body: you get a job_id at once and poll GET https://api.everyinfra.com/api/v1/jobs/{job_id} for the result.
- On 422, fix the request using the suggested parameter names and allowed values in the error; on 429 or 503, wait for Retry-After and try again.

Before writing code, ask me which targets I need, how many, which fields, and what output format I want; then confirm the plan and the rough cost with me.