Not working on 1.20.4
[00:14:15 ERROR]: [ModernPluginLoadingStrategy] Could not load plugin 'pet_teleport.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: Unsupported API version 1.21
at org.bukkit.craftbukkit.v1_20_R3.util.CraftMagicNumbers.checkSupported(CraftMagicNumbers.java:389) ~[paper-1.20.4.jar:git-Paper-497]
at io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider.createInstance(SpigotPluginProvider.java:119) ~[paper-1.20.4.jar:git-Paper-497]
at io.papermc.paper.plugin.provider.type.spigot.SpigotPluginProvider.createInstance(SpigotPluginProvider.java:35) ~[paper-1.20.4.jar:git-Paper-497]
at io.papermc.paper.plugin.entrypoint.strategy.modern.ModernPluginLoadingStrategy.loadProviders(ModernPluginLoadingStrategy.java:116) ~[paper-1.20.4.jar:git-Paper-497]
at io.papermc.paper.plugin.storage.SimpleProviderStorage.enter(SimpleProviderStorage.java:38) ~[paper-1.20.4.jar:git-Paper-497]
at io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.enter(LaunchEntryPointHandler.java:36) ~[paper-1.20.4.jar:git-Paper-497]
at org.bukkit.craftbukkit.v1_20_R3.CraftServer.loadPlugins(CraftServer.java:507) ~[paper-1.20.4.jar:git-Paper-497]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:274) ~[paper-1.20.4.jar:git-Paper-497]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1131) ~[paper-1.20.4.jar:git-Paper-497]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[paper-1.20.4.jar:git-Paper-497]
at java.lang.Thread.run(Unknown Source) ~[?:?]