OptionalexternalA unique alert ID generated by the application developer (maximum length: 32 characters).
OptionalheaderA header text to display in the custom alert (maximum length: 255 characters).
OptionalimageA URL to an image that will be included in the alert (maximum length: 255 characters).
OptionalmessageA message text to display in the custom alert (maximum length: 300 characters).
OptionalshouldDetermines whether the alert should be displayed immediately.
OptionalsoundA URL to a sound file that will play when the custom alert is displayed (maximum length: 255 characters).
Data structure for sending a custom alert to Donation Alerts.