You will be required to top up the card by manually sending funds from your LL app to the card's account address. Those coins will then become spendable with the debit card.
That's about the same as many other card providers offer.
Unless this still applies:
For now we know that crypto will be converted to fiat at the time of purchase happens.
I've never seen a debit card that holds a balance in Bitcoin and converts it only when you make a purchase.