Carrier wants me to upgrade my Iphone 12

Yes, assuming you have signed up for that service with your provider.

More info here: https://support.apple.com/en-gb/HT211828

Hey there,

Yes , iPhone 12 series & later are compatible with 5G technology.

What you need

• An iPhone 12 model or later 
• A network that supports 5G
• A 5G mobile plan1

If your new iPhone comes with a physical SIM or eSIM, use that SIM. If not, use the SIM card from your previous iPhone. In some cases, you need to contact your network provider to set up the SIM card from your previous iPhone for use with a 5G network.

For more info visit ☞ Use 5G with your iPhone – Apple Support (UK)

Yes, assuming you have signed up for that service with your provider.