This is a physical SIM, not a travel eSIM. The product page says the number is already activated before the card ships, and that Wi-Fi Calling can place calls and send texts once the phone is on Wi-Fi. Minutes and coverage are whatever option you bought on the T-Mobile page. They are not repeated here.
Insert the card, then enable Wi-Fi Calling
1Insert the pre-activated card
Every option on sale says it is pre-activated. After you insert it, the phone should see the line. If it does not, start with what to do when a physical SIM arrives before changing other settings.
2Put the phone on Wi-Fi
The product page's condition is a Wi-Fi connection. Mobile data from a travel eSIM is not Wi-Fi and does not replace this step. Home Wi-Fi, hotel Wi-Fi, or another device's hotspot does.
3Turn the switch on for the T-Mobile line only
iPhone: Settings → Cellular, open the T-Mobile line, and turn on Wi-Fi Calling. If the system asks for an emergency address, fill it in. That prompt belongs to the phone. Android labels differ. Search settings for Wi-Fi Calling.
If the switch is on, the phone is on Wi-Fi, and calls or texts still fail, use contact with the order number and the message you see. Physical-SIM returns are in the refund policy.