Message cannot top up your bank card declined

Please can you advise how I resolve. I lost my bank card (not my monzo card) recently so is this why I cannot top up at the moment?
If so how can I update my monzo account details?
Juliaeking@gmail.com

Hi Julia, have you got your new bank card? You will need to tap “Add a new card” on the debit card top-up screen and enter the details of the new card.