On iPhone: check Settings > Celluar and see if the eSIM is there. If it is, make sure the PM eSIM is set as Primary on "Cellular Plan Label" and "Turn on This Line" is toggled on
If you already had a eSim on your phone, but end up getting a new phone you can go ahead and install the Public Mobile App on your new device in this example a iPhone. Then log into the Public Mobile App, then click Account on the bottom, and then ...