Removes the link between a custom object and a target entity for the given relationship field.
If the link does not exist, the operation is idempotent and returns
removed: 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