You could use a coinbase debit card or something like a TenX card that would convert your crypto balance into fiat for you and in that way you could effectively pay for anything that requires fiat using BTC
Yea, the only way for this to work would be to get the btc over to fiat somehow. There are other ways for getting the btc to fiat though. You could just use the currency exchange here as well.
However, if you're trying to ship, the suggestion for a debit card would be the best option for you.