FAQ　

It is a next-generation digital SIM card developed to play the role of an existing physical USIM card generally used for mobile phones. eSIM is installed as a digital chipset on the device. You may download/activate the SIM profile of the carrier from the server of the eSIM provider via the Internet. eSIM is also called the Embedded Universal Circuit Card (eUICC).
As its name the "embedded subscriber identification module (eSIM)" indicates, you do not need to buy an extra physical SIM chip; you can simply download the subscriber's information of the carrier and activate your mobile phone. An easier and quicker method to achieve service activation

To scan a QR code from your iPhone, you can set the focus on the QR code using the default camera app, or go to Settings > Cellular and click Add Cellular Plan at the bottom; a QR code scanner will pop up. At this time, the iPhone must be connected to the Internet to scan/activate the eSIM.

It’s easier to switch networks. An eSIM makes it much easier to switch mobile networks.
You can temporary change to another network. Up to five virtual SIM cards can be stored on one eSIM at a time.
Allows you to have more than one SIM. eSIMs also offer the same advantages as dual-SIM phones with two slots for traditional plastic SIMs, the most obvious being that you can have two phone numbers on one device.
Uses less physical phone space. Another advantage of eSIMs is that they will eventually negate the need for a physical SIM card and its tray.

As the Tplus eSIM service is a service provided by a domestic MVNO operator, you are unable to use it abroad.

Apple iPhone XR and later versions. It can be used on the devices with iOS 12.1.1 or higher.
Go to your iPhone's Settings >General >Info ; if you can see "Digital SIM Info" there, you may use our eSIM service on your device.

eSIMs can be installed on only one device, and most eSIMs can be installed only once, which means that if you remove the eSIM from your device it will not be possible to install it again.

There are two lines (main and secondary) that can be used simultaneously on your iPhone; one is used for a physical USIM card and the other is used for eSIM. Up to 10 eSIMs can be stored and used on either the main line or secondary line.