When i load minecraft server fabric 1.21.1 + Cardboard 1.21.1-1 i see this in logs:

[12:58:10] [main/INFO]: Debug: Loading library paper-api-1.20.6-R0.1-20240916.192025-126.jar

Maybe it is reason why i have these issue:

[12:58:53] [Server thread/FATAL]: Could not load 'plugins\AxiomPaper-4.0.1-for-MC1.21.1.jar'
org.bukkit.plugin.InvalidPluginException: Unsupported API version 1.21
at knot/org.bukkit.craftbukkit.util.CraftMagicNumbers.checkSupported(CraftMagicNumbers.java:538) ~[Cardboard-1.21.jar:?]
at knot/org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:140) ~[Cardboard-1.21.jar:?]
at knot/org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:1439) ~[paper-api-1.20.6-R0.1-20240916.192025-126.jar:?]
at knot/org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:1356) ~[paper-api-1.20.6-R0.1-20240916.192025-126.jar:?]
at knot/org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:1163) ~[paper-api-1.20.6-R0.1-20240916.192025-126.jar:?]
at knot/org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:513) ~[Cardboard-1.21.jar:?]
at knot/net.minecraft.class_3176.handler$zco000$cardboard$init(class_3176.java:786) ~[server-intermediary.jar:?]
at knot/net.minecraft.class_3176.method_3823(class_3176.java:161) ~[server-intermediary.jar:?]
at knot/net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:664) ~[server-intermediary.jar:?]
at knot/net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:281) ~[server-intermediary.jar:?]
at java.base/java.lang.Thread.run(Thread.java:1583) [?:?]