Hello , I am an iPhone 11 user, I suffer from the problem of not having the option to add a cellular plan to scan the barcode of the electronic chip in the device. I updated the phone to the latest version

Hey there,

To use two different carriers, your iPhone must be unlocked. Otherwise, both plans must be from the same carrier. If a CDMA carrier provides your first SIM, your second SIM won't support CDMA. Contact your carrier for more information. 

If you have an enterprise or corporate cellular service plan, check with your company administrator to see if they support this feature.

See ☞ Using Dual SIM with an eSIM - Apple Support