We don't offer ATM cash withdrawals on your HSA debit card.
This is a measure to protect you (and us) from fraud. If your card were ever lost or stolen, we don't want an unauthorized person cashing out your account!
In the (very highly unlikely) event that you have a 'cash only' qualified health expense, you can always pay out of pocket and then reimburse yourself from your HSA. Remember to keep your receipts!