Here's how to install the T-Mobile eSIM on your iPhone
Between 2am-6am US Pacific Time on the date you requested for eSIM activation, a notification will appear on your iPhone like shown below. Simply tap the notification and follow the instructions.
You can also swipe from the top down to access all your notifications to find the eSIM notification like shown below. Simply tap the notification and follow the instructions.
You can also go into Settings and tap the red "Set Up Mobile" notification like shown below. Simply tap the notification and follow the instructions.
What happens if you don't get the notification? Here's what to do:
(1) Try restarting your phone and connecting to a working Wi-Fi network and check for the notification.
(2) If you still don't see the notification, reset the network settings on your iPhone (Google search if unsure how to do this), then connect to a working Wi-Fi network and check for the notification.