I need help with countdown

Hello I just would like to know how can I do this countdown on pocketmine?

https://forums.pocketmine.net/threads/creating-a-timer-with-tasks.11098/
Run a task every few ticks to sendTip to the player

Thanks but how can I add it with that little bar?

PHP:

$player->sendTip(TextFormat::GREEN.str_repeat('|',$tick).TextFormat::RED.str_repeat('|',$max - $tick));

where $tick is the current tick and $max is the max number of '|' you want to see

Thank you