HAHAHAH It's just a slang, you can't translate every word cause it doesn't make any sense. I always take care here to not say things that I'm not sure if everyone would understand.
But that slang means something like: You are making up things, this thing it's not true, it's something only from your mind.
And I'm seeing a lot of Brazilians here at MT, oi gente! (Quem sabe até podemos criar um canal no Discord?)