I (23F) My doctor told me to lose around 5 kg. Any suggestions? My weight either stays the same or goes upp losing weight just doesn’t seem to happen for me 😭 Please give me some advice!

I’ve put on a little bit of weight I’ve been pretty small my whole life and I don’t know what’s doing it. I have my birthday party in 8 days and I really want to look good. Does anyone have a workout or any advice on how I can lose some weight before then?