As far as I understand they don't have IBAN like the polish cards.
But are interesting nonetheless and would be cool to have someone selling them for a good price.
I also do not think the have an Iban. Only a CZ bank account. Maybe you can convert it to an Iban, but i am not sure about that!
You will neet a CZ Sim card also. For a small tip i can show you where you get card+ sim REALLY cheap. Also high amounts if you want to resell them.
Czech Republic is a SEPA country so it has IBAN.
It's fairly easy to convert. Check here:
https://www.cnb.cz/en/payment_systems/iban/IBAN_international_account_number.html
To calculate:
https://www.cnb.cz/en/payment_systems/iban/ibanen.html
or
http://www.ibancalculator.com/bic_und_iban.html