How does Coinbase card work?

Could you elaborate on the functionality of the Coinbase card? As a user interested in cryptocurrency payments, I'm curious about how the Coinbase card integrates with my digital wallet. Specifically, how do I fund the card with my crypto holdings? Are there any fees associated with transactions using the Coinbase card? Additionally, are there any limitations on where I can use the card, or are there merchants that specifically accept it? Understanding the intricacies of how the Coinbase card operates would greatly assist me in deciding whether it's a suitable payment method for my needs.