For IOS: proceed to your phone settings > mobile/cellular data, if it has Add eSIM option, it is compatible.

Also, check if your phone is locked or not. Go to Settings > General, and tap About. Under Carrier Lock, you should see a message that says "No SIM restrictions."

For Android: proceed to your phone settings > Connections/Phone/More connections/SIM card Manager, if it has eSIM section, it is compatible.

Which mobile devices are compatible with the eSIM?