curl --request GET \
  --url https://pro-api.coingecko.com/api/v3/key \
  --header 'x-cg-pro-api-key: <api-key>'

{
  "plan": "Other",
  "rate_limit_request_per_minute": 1000,
  "monthly_call_credit": 1000000,
  "current_total_monthly_calls": 32,
  "current_remaining_monthly_calls": 999968,
  "api_key_rate_limit_request_per_minute": 1000,
  "api_key_monthly_call_credit": 1000000,
  "api_key_current_total_monthly_calls": 8
}