For assistance, please visit one of our authorized Service Centres to check it for you. You may refer to the link it will guide you to the nearest service centre to your location https://www.samsung.com/ae/support/service-center/
First, check whether you have esim feature on Note 20 ultra. For that you can head to settings >> Connections >>Sim card manager >> eSIMs (Add esim). If yes. Then contact your network provider and get your physical sim converted to esim. Then scan the provided QR code and use it.