N8N API integration Fix

We need a developer to troubleshoot and fix an existing N8N workflow that is not sending data correctly to an external API. The work includes identifying the root cause, correcting the integration, and verifying that data flows successfully from the workflow to the target system. You should be comfortable reviewing current setup, debugging API requests, and making the necessary adjustments to restore reliable communication. Please share relevant experience with workflow automation and API troubleshooting.