No! That's confusing. Your system already converts BTC to USD when you deposit BTC and then use it to charge your card.

What would be better is if you allow USDT-TRON as a coin in your wallet (USDT-TRON has virtually no blockchain fees and it's fast). Then you can put stable coin in your wallet without having to worry about the fluctuations in price. You could add way more than you need to your wallet, and then charge your card whenever you are running low.