This study will compare two different ways of giving cagrilintide and semaglutide for treating overweight and obesity. The medicines will either be given together in 1 injection or as 2 separate injections. The aim of the study is to find out how the different ways of injection affect the level of the medicines in the blood. For the first 14 weeks of the study, participants will get cagrilintide and semaglutide as 2 separate injections. Then participants will either switch to getting the medicines as a combined injection or continue to get the separate injections for 8 weeks. Which treatment participants get after the first 14 weeks is decided by chance. Participants will get the study medicines once a week for 22 weeks. A study nurse at the clinic will inject the medicines with a thin needle in participants stomach area. The study will last for about 8 months.Participants will have 28 clinic visits with the study staff. For 4 of these visits, participants will stay in the clinic for 5 nights. Participants will have blood drawn at 21 visits. Participants will have clinical assessments and participants will be asked about their health, medical history and habits including mental health questionnaires. For women: Participants must not be able to become pregnant if they wish to participate in this study.