ExBinance.Private.query_order_by_client_order_id

You're seeing just the function query_order_by_client_order_id, go back to ExBinance.Private module for more information.
Link to this function

query_order_by_client_order_id(symbol, client_order_id, credentials)

See ExBinance.Rest.QueryOrder.query_order_by_client_order_id/3.