Please help me with this import

[LJForge]

This is my code:

private void addCreative(Register<Block> event) {
        if (event.getTab() == CreativeModeTabs.BUILDING_BLOCKS)
            event.register(EXAMPLE_BLOCK);
    }

Cannot resolve symbol 'Register'

 

How do I fix? I have tried the import

import net.minecraftforge.registries.Register;

but it doesn't work.

 

I also have these problems on that same code:
Cannot resolve method 'getTab()'

Cannot resolve method 'register(RegistryObject<Block>)'