How to earn interest on Euro Account or Deposits?

I'm currently holding ING PLN account and EUR (account? wallet?). Bank told me that I can earn interest only on PLN and EUR is just a wallet.

Is there any bank in Poland which offers interests on EUR accounts or EUR Fixed Deposits?

That will be difficult - You will need many thousands of Euro to earn anything worthwhile. Only three banks earn more than 0.50 on Euro fixed deposits and they are all Polish owned.

On current accounts just forget it - and work instead to ensure you don't pay any fees. When they say it's a wallet they are talking metaphorically.

There is zero interest rate policy in the eurozone so so won't find any interest paying accounts without a long lock-up period and even then a measely rate offered. You can however earn 2% PLN in the new polish postoffice online bank and there is no upper limit!

Thank you @cms & @polishinvestor
So the only option is to convert them to PLN and do a fixed deposit.

What would be the link to that online post office bank as well as the requirements to open and account?