You can check how much data is left in your bundle by dialing the shortcode *187# from your phone in exactly the same way that you would dial a telephone number. However you must make sure that the eSIM plan is selected as the plan used to dial the number ( see the screenshot below ).
You will then receive a message on the screen telling you how much data is left in your plan, whether the plan has been first used and the expiry date of your plan – see below.
If the plan has not been first used yet then the expiry date is meaningless and the expiry period only starts once the plan is first used.