Problem setting fire to air after a specific amount of time

I need help setting fire to air after 5 seconds. Could someone correct me.

Code:

package me.trytan.iffa.Events;

import me.trytan.iffa.Main;

import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.block.BlockPlaceEvent;

public class Fire_Event implements Listener{
   
    Main pl;
   
    @EventHandler
    public void onPlace(final BlockPlaceEvent e){
        if(e.getBlock().getType() == Material.FIRE){
            Bukkit.getServer().getScheduler().scheduleAsyncDelayedTask(pl, new Runnable(){
                public void run() {
                    e.getBlock().setType(Material.AIR);
                }
               
            }, 50L);
        }
    }

}

 

@Trytan
Do NOT use an Async task for that.

Use sync task.

 

Also Main pl; is null so your scheduler will not work
And 50L is 2.5 seconds. It is in ticks (20 ticks = 1 second) so you need 100L or 5L * 20L