This study is testing a new study medicine to treat people living with overweight or obesity. The aim of this study is to see if the medicine is safe, how it works in human body, and what human body does to the study medicine. Participants will either get the new study medicine NNC0174-1213, a study medicine called "cagrilintide" or a placebo (a "dummy medicine" similar to the new study medicine and study medicine but without active ingredients). Which treatment participants will get is decided by chance. The new study medicine and the study medicine are potential new medicines which cannot be prescribed by doctors. This study will last for about a year in total.