Overview
The guide describes parameter combinations the API does not support and explains how to resolve related errors.Retail Price Improvement (RPI) and IOC
RPI orders use post-only behavior by design. An RPI order does not support the IOC flag.Issue
A request sets bothrpi=true and ioc=true.
Result
The API rejects the request and returns error code37.
Fix
Removeioc when using rpi, or disable rpi when IOC behavior is required.