ICCID is the unique 20-digit serial number of your SIM card, both physical and eSIM, which starts with the number 89 and looks like this 89ХХХХХХХХХХХХХ.
The ICCID Zadarma's eSIM number can be found in the settings of your mobile phone. First make sure the eSIM is connected and active.
How to find the eSIM ICCID on iPhone?
Go to Settings - General - About - Travel
How to find eSIM ICCID on Android devices?
All Android devices vary depending on the phone brand and firmware version, for example for Samsung phones the path usually looks like this:
Settings – Connections – SIM card manager – then you need to select your eSIM.