Optionalgiveaway_Message with the giveaway that was completed, if it wasn't deleted.
Optionalis_True, if the giveaway is a Telegram Star giveaway. Otherwise, currently, the giveaway is a Telegram Premium giveaway.
Optionalunclaimed_Number of undistributed prizes.
Number of winners in the giveaway.
This object represents a service message about the completion of a giveaway without public winners.
See
Telegram Bot API: GiveawayCompleted