GLP-1 medications slow the rate at which the stomach empties and food moves through the gut. For some people that shows up as constipation, most often in the first weeks of treatment or after a dose change. It is one of the more common side effects listed in the prescribing information for these medications.
Constipation that is not addressed can become uncomfortable and, rarely, lead to complications, so it is worth acting early and telling your provider if it persists.