Sample mode: checkout takes test orders only until payments go live.

Is your phone ready for an eSIM?

Does it support eSIM?

iPhone: iPhone XS, XR and every later model support eSIM. In Settings › Cellular you will see Add eSIM.
Android: dial *#06#. If the screen shows an EID number, the phone has an eSIM. Google Pixel 3 and later and many Samsung Galaxy S20 and later models have one, but some regional variants do not.

Is it unlocked?

iPhone: Settings › General › About › Carrier Lock should say No SIM restrictions.
Android: there is no single screen for this. A phone bought outright from the maker is normally unlocked; a phone bought on a carrier contract may not be. Your carrier can confirm and unlock it.

Both checks pass?

Pick a destination from the list of countries. After payment you get an install page with the QR code; installing takes a minute.