An Update is Required to Use Cellular Data on this iPhone

hi !! i tried the ff but it still won’t work:

• Toggle Airplane Mode on and off again

• Restart your iPhone

• Update your phone & carrier settings update is not available. My phone update is 15.2.

• Remove the SIM and put it back

• Reset network settings

• I tried connecting it to my laptop to download and reinstall the current version of software on my device but it still won’t work.

what could be the problem of my phone? and how much would the repairs be?