Use the field's stable slug as the JSON key when n8n writes a Busabase record. The visible field name can change from “Customer name” to “Company name” while a slug such as customer_name stays the same. Neither the display label nor the field's internal ID is the key in a record payload. Recheck the mapping if someone deletes and recreates the field or changes the integration's actual slug.
For an update, POST /api/v1/records/{recordId}/change-requests with a body like this, replacing the record ID in the URL and the slug with your actual values:
{"operation":"update","fields":{"customer_name":"Acme"},"message":"Update company name","autoMerge":false}
Save the returned Change Request ID. Open it in Inbox to compare before/after values, or GET /api/v1/change-requests/{changeRequestId} to inspect the submitted operation's field keys and values. A successful submission can still be awaiting review; test one record end to end before changing the n8n workflow.