unpinAllChatMessages method
Use this method to clear the list of pinned messages in a chat.
If the chat is not a private chat, the bot must be an administrator in the chat for this to work and must have the 'can_pin_messages' administrator right in a supergroup or 'can_edit_messages' administrator right in a channel.
Returns True on success.
Implementation
Future<bool> unpinAllChatMessages(ChatID chatId) {
return _client.apiCall(_token, 'unpinAllChatMessages', {
'chat_id': chatId,
});
}