Could not load plugin

Hey, I wanted to create a plugin but I get this error in the console:

Code:

[18:52:26] [Server thread/WARN]: Legacy plugin DumbPlugin v1.0.0 does not specify an api-version.
[18:52:26] [Server thread/ERROR]: Could not load 'plugins\DumbPlugin.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.UnsupportedClassVersionError: com/github/krystianwiechec/DumbPlugin/main/Main has been compiled by a more recent version of the Java Runtime (class file version 57.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:139) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:394) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:301) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at org.bukkit.craftbukkit.v1_16_R2.CraftServer.loadPlugins(CraftServer.java:381) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at net.minecraft.server.v1_16_R2.DedicatedServer.init(DedicatedServer.java:186) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at net.minecraft.server.v1_16_R2.MinecraftServer.w(MinecraftServer.java:808) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at net.minecraft.server.v1_16_R2.MinecraftServer.lambda$0(MinecraftServer.java:164) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_261]
Caused by: java.lang.UnsupportedClassVersionError: com/github/krystianwiechec/DumbPlugin/main/Main has been compiled by a more recent version of the Java Runtime (class file version 57.0), this version of the Java Runtime only recognizes class file versions up to 52.0
        at java.lang.ClassLoader.defineClass1(Native Method) ~[?:1.8.0_261]
        at java.lang.ClassLoader.defineClass(Unknown Source) ~[?:1.8.0_261]
        at java.security.SecureClassLoader.defineClass(Unknown Source) ~[?:1.8.0_261]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:163) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:96) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_261]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_261]
        at java.lang.Class.forName0(Native Method) ~[?:1.8.0_261]
        at java.lang.Class.forName(Unknown Source) ~[?:1.8.0_261]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:64) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:135) ~[spigot-1.16.2.jar:git-Spigot-379750e-43c7ff9]
        ... 7 more

my Main class looks like this:

Code:

package com.github.krystianwiechec.DumbPlugin.main;
import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin {

@Override
public void onEnable() { }

@Override
public void onDisable() {}

}

and plugin.yml like this:

Code:

name: DumbPlugin
main: com.github.krystianwiechec.DumbPlugin.main.Main
version: 1.0.0
description: This plugin is dumb

Anyone know why is getting this error?

 

Ok, so what do I have to do to make it work?