Bitcoin is already the de facto currency.
You can use your cash app to scan the QR code when you try to finish payment, It will auto guide you to finish the payment. You can also take a look at this video.
https://www.youtube.com/watch?v=r5mOeYK60CE
We have quite a few customers who started using bitcoin to pay for orders.
It's a famous and popular transaction method as the best next generation transaction resolution. It's much easier than credit card and bank transfer with low transaction fees.
You can get bitcoin amount and address from your order details after you changed the payment method to bitcoin payment.
You can buy bitcoins from the following company or any similar websites
https://www.moonpay.com/buy/btc
https://www.binance.us/en/buy-sell-crypto (U.S only)
https://p2p.binance.com/en/express/buy/BTC/USD (Non-U.S)
For australia, you can buy bitcoin from the following websites:
https://buy.bitcoin.com.au/
https://paybtc.com.au/
For canada, you can buy bitcoin from:
https://www.coinberry.com/prices
https://www.coinsmart.com/