Create or update an Attribution record on the given Contribution for a Person.
If there is an existing Attribution for the given Person on the given Contribution, it will be updated to match the Attribution provided with this request. If there is not an existing Attribution, one will be created.
Accepts an Attribution object. The vanId property of the Attribution object must match the value of the vanId parameter provided in the route. If amountAttributed is not provided, it will default to the remaining amount of the Contribution. If attributionType is not provided, it will default to DefaultAttribution.
If the specified Contribution or Person does not exist, this endpoint will return an error with HTTP Status Code 404 Not Found.
If successful, the endpoint responds with HTTP Status Code 204 No Content if an existing Attribution has been updated. If a new Attribution has been created, this endpoint responds with HTTP Status Code 201 Created.