In the cart, at the 1st step of the order processing you can: tick the product to continue placing the order, check your order, if necessary change the quantity of the product or delete the product, if you change your mind.
You Must submit the EXACT Amount of Bitcoin Or Any Altcoin as requested. DO NOT ALLOW your wallet to convert dollars to Bitcoin – the calculation will probably be wrong and not processed by CoinPayments.
Copy the wallet address and amount of Bitcoin required as indicated and send the EXACT amount of Bitcoin indicated.