Error occuring when trying to access the GUI using /boosters on 1.19

[TheNamesArthur]

[19:59:14 INFO]: TheNamesArthur issued server command: /boosters
[19:59:14 ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'boosters' in plugin Boosters v4.51.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:47) ~[paper-api-1.19-R0.1-SNAPSHOT.jar:?]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:155) ~[paper-api-1.19-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.v1_19_R1.CraftServer.dispatchCommand(CraftServer.java:909) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.server.network.ServerGamePacketListenerImpl.handleCommand(ServerGamePacketListenerImpl.java:2382) ~[?:?]
at net.minecraft.server.network.ServerGamePacketListenerImpl.lambda$handleChatCommand$18(ServerGamePacketListenerImpl.java:2153) ~[?:?]
at net.minecraft.server.TickTask.run(TickTask.java:18) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.util.thread.BlockableEventLoop.doRunTask(BlockableEventLoop.java:153) ~[?:?]
at net.minecraft.util.thread.ReentrantBlockableEventLoop.doRunTask(ReentrantBlockableEventLoop.java:24) ~[?:?]
at net.minecraft.server.MinecraftServer.doRunTask(MinecraftServer.java:1359) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:183) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.util.thread.BlockableEventLoop.pollTask(BlockableEventLoop.java:126) ~[?:?]
at net.minecraft.server.MinecraftServer.pollTaskInternal(MinecraftServer.java:1336) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.server.MinecraftServer.pollTask(MinecraftServer.java:1329) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.util.thread.BlockableEventLoop.managedBlock(BlockableEventLoop.java:136) ~[?:?]
at net.minecraft.server.MinecraftServer.waitUntilNextTick(MinecraftServer.java:1307) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1192) ~[paper-1.19.jar:git-Paper-81]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:303) ~[paper-1.19.jar:git-Paper-81]
at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: kotlin.UninitializedPropertyAccessException: lateinit property gui has not been initialized
at com.willfp.boosters.gui.BoosterGUI.open(BoosterGUI.kt:79) ~[Boosters v4.51.0.jar:?]
at com.willfp.boosters.commands.CommandBoosters.onExecute(CommandBoosters.kt:30) ~[Boosters v4.51.0.jar:?]
at com.willfp.eco.core.command.impl.HandledCommand.handle(HandledCommand.java:147) ~[eco-6.38.3-all.jar:?]
at com.willfp.eco.core.command.impl.PluginCommand.onCommand(PluginCommand.java:70) ~[eco-6.38.3-all.jar:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:45) ~[paper-api-1.19-R0.1-SNAPSHOT.jar:?]