I think the title says it all. They have created a tutorial on resources on how to create a task, only it is schedulerRepeatingTask, and I need a SchedulerDaleyedTask, if you can tell me how it does it, I appreciate it.
Same as a repeating task except the method for scheduling a delayed task is different. See it here: https://github.com/pmmp/PocketMine-MP/blob/master/src/pocketmine/scheduler/ServerScheduler.php#L195
schedule-delayed and schedule-delayed are the actions. Task is the noun. You can only create a Task, and you can only do a task delay-scheduling or a task repeat-scheduling, but you can't create it. While this sounds nonsense, it is very important to how you understand how it works. Just like you can build a cannon, but you can't create a TNT cannon. You can only build a cannon and fill it with TNT, but TNT isn't part of the cannon itself.