Cannot import net.minecraft.world.item.SwordItem

I've just started modding, and I'm trying to make custom swords. When I try to import SwordItem, I get the error: 

Quote

The import net.minecraft.world.item.SwordItem cannot be resolvedJava(268435846)

What confuses me is that other item classes work fine:

package io.github.xxx.denseswords.item;

import io.github.xxx.denseswords.DenseSwords;
import net.minecraft.world.item.Item; // works fine
import net.minecraft.world.item.ShovelItem; // works fine
import net.minecraft.world.item.SwordItem; // Error: The import cannot be resolved
import net.minecraftforge.registries.DeferredRegister;
import net.minecraftforge.registries.RegistryObject;

Forge MDK v55.0.15 - Minecraft 1.21.5

Java v24.0.1

Windows 11

IDE: Visual Studio Code