No – you can't add cash to your Builder card's security deposit outside of the Cleo app.
If you do go to a store, kiosk, or another app to do this, the transaction could go through from your debit card (or the app could inform you that your paper check has been deposited here), but it won't get added to your security deposit. Getting this money back can be frustrating and difficult. This also means Cleo won't have any record of this transaction.
How do I add cash to my Builder card's security deposit?
Go to the Spend tab, and at the bottom left underneath your card you should see an "Add cash" button.
Tap "Add cash" and choose the method by which you want to add cash to your card's security deposit.