No, you’ll need a new phone as older phones can’t be updated to support 5G because they require a 5G chipset and modem . If you have a 3G or 4G phone it will still work on 5G plans, but you’ll only get 3G or 4G speeds.
Read moreHow do I upgrade my phone to 5G?
Go to Settings > Cellular > Cellular Data Options . If you see this screen, your device has 5G activated. If you don’t see this screen, contact your carrier to confirm that your plan supports 5G. Turn on Airplane Mode, then turn it off.
Read more