This study will look if CagriSema can lower kidney damage in people with chronic kidney disease (CKD), type 2 diabetes (T2D) and overweight or obesity. CagriSema is a new investigational medicine. CagriSema cannot yet be prescribed by doctors. The study will compare CagriSema to the 2 medicines semaglutide and cagrilintide, when they are taken alone. It will also compare CagriSema to a "dummy" medicine (also called placebo) without any active ingredient. Participant will either get CagriSema, semaglutide, cagrilintide or placebo. Which treatment participant will get is decided by chance (like flipping a coin). Study doctor will not know which of the study medicines participant will get. For each participant, the study will last for about 35 weeks.