Error on Plugin enable

[vxnsin]

I Install ShopChest on a 1.15.2 Paperspigot Minecraft Server
The Error is:

[coolternet]

same thing on 1.21.11

[02:29:14] [Server thread/INFO]: [ShopChest] Enabling ShopChest v1.12.3* [02:29:14] [Server thread/WARN]: [ShopChest] Server version not officially supported: craftbukkit! [02:29:14] [Server thread/WARN]: [ShopChest] Plugin may still work, but more errors are expected! [02:29:14] [Server thread/ERROR]: Error occurred while enabling ShopChest v1.12.3 (Is it up to date?) java.lang.NoSuchMethodError: 'com.sk89q.worldguard.protection.managers.RegionManager com.sk89q.worldguard.bukkit.WorldGuardPlugin.getRegionManager(org.bukkit.World)' at ShopChest.jar//de.epiceric.shopchest.ShopChest.loadExternalPlugins(ShopChest.java:217) ~[?:?] at ShopChest.jar//de.epiceric.shopchest.ShopChest.onEnable(ShopChest.java:155) ~[?:?] at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:279) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?] at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:520) ~[paper-api-1.21.11-R0.1-SNAPSHOT.jar:?] at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:639) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:596) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at net.minecraft.server.MinecraftServer.initPostWorld(MinecraftServer.java:636) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:365) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1258) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at net.minecraft.server.MinecraftServer.lambda$spin$2(MinecraftServer.java:388) ~[paper-1.21.11.jar:1.21.11-100-4873e3f] at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?] [02:29:14] [Server thread/INFO]: [ShopChest] Disabling ShopChest v1.12.3