We are doing this study to learn more about how semaglutide may help fight chronic kidney disease in people with type 2 diabetes. We are doing this by looking into how semaglutide works in the kidneys. Participants will either get semaglutide or placebo (a 'dummy' medicine) - which treatment participants get is decided by chance. Semaglutide is a medicine doctors can prescribe in some countries for the treatment of type 2 diabetes. Participants will get the study medicine in a pen. Participants will use the pen to inject the medicine into the skin once a week. The study will last for about 1 year. Participants will have 11 visits to the clinic, and 2 phone visits. Some of the visits could be in different locations. Study staff will take blood samples at most of these visits. At 9 visits, participants will be asked to bring a sample of their first morning urine. At 4 of the visits participants will have to bring urine that they have collected over the last 24 hours. The study includes magnetic resonance imaging (MRI) scans of participants' kidneys which is a test that shows a detailed picture of organs and other parts inside the body. The scan will last for 30 minutes, and is free of radiation.