Minecraft mcreator java code errors

package net.mcreator.superflatplus;

import net.minecraft.core.Registry;
import net.minecraft.resources.ResourceKey;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.world.level.biome.Biome;
import net.minecraft.world.level.levelgen.structure.Structure;
import net.neoforged.neoforge.common.world.modification.BiomeModifier;
import net.neoforged.neoforge.common.world.modification.StructureAdditionBiomeModifier;
import net.neoforged.neoforge.common.world.modification.WorldModifications;

public class ForceStructureToSpawn {

    public static void init() {
        // Plains biome key
        ResourceKey<Biome> plainsBiome = ResourceKey.create(Registry.BIOME_REGISTRY, new ResourceLocation("minecraft", "plains"));
        // Ancient City structure key
        ResourceKey<Structure> ancientCityStructure = ResourceKey.create(Registry.STRUCTURE_REGISTRY, new ResourceLocation("minecraft", "ancient_city"));

        // Create the biome modifier that adds Ancient City to Plains biome
        BiomeModifier modifier = new StructureAdditionBiomeModifier(plainsBiome, ancientCityStructure);

        // Register the biome modifier globally
        WorldModifications.addGlobalBiomeModifier(modifier);
    }
}