A Research Study of NNC0165-1875 Alone or Together With Semaglutide in People Who Are Overweight or Obese

The study is looking at possible new medicines for weight control in people with high body weight. The study looks at how the new medicines work in the body. The study consists of two parts. If participants take part in Part 1, they will either get a single dose of NNC0165-1875 or a "dummy" medicine (placebo). If participants take part in Part 2, they will either get a single dose of NNC0165-1875 or "dummy" medicine and also a single dose of semaglutide. Which treatment participants get is decided by chance. For Part 1 participants will get 1 injection. For Part 2 participants will get 2 injections. A study nurse at the clinic will inject the medicine with a thin needle in a skin fold in the stomach. The study will last for about 9 weeks. Participants will have 7 visits to the clinic with the study doctor.