Create: Associates the given data with the specified beacon. Attachment data must contain two parts: - A namespaced type. - The actual attachment data itself. The namespaced type consists of two parts, the namespace and the type. The namespace must be one of the values returned by the `namespaces` endpoint, while the type can be a string of any characters except for the forward slash (`/`) up to 100 characters in length. Attachment data can be up to 1024 bytes long. Authenticate using an [OAuth access token](https://developers.google.com/identity/protocols/OAuth2) from a signed-in user with **Is owner** or **Can edit** permissions in the Google Developers Console project.