Facebook Marketplace API

Please help me write a data collection script with the EveryInfra Facebook Marketplace endpoint (facebook/marketplace).

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 facebook and action to marketplace, and put the parameters inside params.
- Required parameters:
  - keyword: Specifies the search query for distinct platform endpoints. For search, it searches public posts; for ads, it accepts ad keywords or direct Ad Library and Page URLs.
- Optional parameters:
  - location: Specifies the city path identifier for marketplace, such as nyc (defaults to nyc). It does not accept free-form street addresses.
  - limit: The most rows to return in this call, an integer from 1 to 200. The default applies when you leave it out, and a call can return fewer rows. Larger values return 422 before any charge. (default: 20)
- Returns a list of records. Main fields of each record: id, url, name, price, currency, city, state, condition, image_url, posted_at.
- Example request body:
{
  "platform": "facebook",
  "action": "marketplace",
  "params": {
    "keyword": "coffee"
  }
}
- Price: $1.39 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.