The anonymous Bitsa card is a prepaid card issued by Visa that can be recharged with fiat money (euros) and is associated with your Bitsa account without having a personal bank account.
Remember that you can only have a physical anonymous card in your account.
For your security, behind your card, there is an EDE (Electronic Money Entity) approved by the Bank of Spain that holds your funds.
In addition, if you wish, you can also ask for physical cards with your name on them.
Depending on the plan you have subscribed to, you can have several nominative physical cards.