What the?
Yes, you can give money to paypal via credit card, even if that credit card happens to be a debit card.
But this does not mean you can use your atm card number. Either your card is an internationally valid card or not. My guess is, it is not. If it were you would have a security number on the back. But even if it were a local card, paypal does offer local available payment options.
But you do not need a card. Just tell paypal to collect money from your bank account.
I am still baffled how you paid previously "with your card". What were the security measures? Did you have to enter a password or how did this work? Was it a sepa transaction?