invite method
Invites Users top this channel.
Implementation
Future<void> invite(List<String> userIds) async {
  sbLog.i(StackTrace.current, 'userIds: $userIds');
  if (userIds.isEmpty) {
    throw InvalidParameterException();
  }
  await chat.apiClient.send(GroupChannelInviteRequest(
    chat,
    userIds: userIds,
    channelUrl: channelUrl,
  ));
}