eSIM question

Here are the steps on how to swap your device online. The full article can be found at https://www.xfinity.com/mobile/support/article/bring-your-own-phone-details.

Bring a device to an existing line using the Xfinity app

To update an existing Xfinity Mobile line with a device you already own, you can use an existing device that has the Xfinity app installed or the phone you want to activate to complete this process.
Sign in to the Xfinity app using the Primary user’s Xfinity ID and password.
Select the Services tab.
Select the Mobile lines and data usage option located within the Mobile services card.
Select the phone line you’d like to update with a BYOD, then select your device to proceed.
Navigate to the Device Management section and select Upgrade or switch your device. You may be required to sign in again.
Select Bring Your Own.
Select the type of device you to which you are switching, and then select Next.
Enter the device’s IMEI.
Follow the activation instructions.
Download an eSIM or insert or swap an Xfinity Mobile nanoSIM Card.

Bring a device to an existing line using the Xfinity Mobile website

To update an existing Xfinity Mobile line with a device you already own through xfinity.com/mobile, log in to your account and visit the Devices page to set up your phone on that line.
Sign in with your Xfinity ID.
Select the device you are replacing.
Select Replace your Device.
Select Bring Your Own.
Select the type of device to which you are switching.
Enter the device’s IMEI.
Follow the activation instructions.
Download an eSIM or insert or swap an Xfinity Mobile nanoSIM Card.