Links a custom object to a target entity via a relationship field. Use
the fieldRefId from the
Get Configuration
endpoint.
Cardinality behavior:
If the exact same link already exists, the operation is idempotent and
returns created: false.
Required permission: company.fmv1_custom_object:update
API key authentication. Include your API key in the Authorization header.
Company identifier
Custom object type in snake_case format (e.g., vehicle, building_info)
Custom object identifier
Relationship field reference ID from the configuration endpoint
Target custom object identifier to link or unlink