We get it, remembering usernames and passwords can be difficult.
If you don't know the answer to your security question(s) or the credentials you use for online banking, you'll want to check in with your bank. They have full visibility to this information and can support you throughout the way.
If you have to change your online banking credentials after contacting your bank, please use your new credentials to link the account.
To link a card to Drop, tap: Profile (top-left) > Link a Card > Choose your bank, and enter your credentials.