Client Area WHMCS Invoice Payment with NOWPayments NOWPayments Payment Gateway WHMCS Order now | Download | FAQ When a customer selects NOWPayments as their payment method on the invoice page, they will see a user-friendly cryptocurrency payment interface with the following features: Cryptocurrency Selection: A dropdown menu displaying 200+ supported cryptocurrencies (BTC, ETH, USDT, DOGE, etc.) for the customer to choose from. Real-time Exchange Rates: The system automatically fetches current exchange rates from NOWPayments API to provide accurate conversion amounts. Estimated Amount Display: Shows the exact amount of cryptocurrency the customer needs to pay based on their selection and current market rates. Loading Indicators: Professional spinner animations while the system loads available currencies and calculates exchange rates. Secure Payment Processing: One-click payment button that redirects to NOWPayments secure payment page. Payment Process Flow Page Load: When the invoice page loads, the system displays a loading spinner while fetching available cryptocurrencies from NOWPayments API. Currency Loading: The dropdown menu is populated with all supported cryptocurrencies (BTC, USDC, FUN, THETA, XRP, DOGE, ETH, and 200+ others). Default Selection: The first available currency (typically BTC) is automatically selected and the system calculates the estimated amount. Rate Calculation: When a customer selects a different cryptocurrency, the system automatically fetches the current exchange rate and updates the estimated amount in real-time. Amount Display: The interface shows both the original invoice amount (e.g., "1.18 EUR") and the estimated cryptocurrency amount (e.g., "0.00001232 BTC"). Payment Initiation: When the customer clicks "Pay Now", they are redirected to the NOWPayments secure payment page to complete the transaction. User Interface Elements Payment Box: A clean, bordered container with light gray background that contains all payment options and information. Currency Dropdown: A responsive dropdown menu that lists all available cryptocurrencies in uppercase format for easy selection. Amount Information: Clear display of the original invoice amount and the calculated cryptocurrency equivalent. Pay Now Button: A prominent blue button with dollar sign icon that initiates the payment process. Loading States: Professional spinner animations (large and small variants) that provide visual feedback during API calls. Error Messages: Red-colored error messages that appear if there are issues with currency loading or rate calculation. Technical Features AJAX Integration: The interface uses asynchronous JavaScript to fetch currencies and exchange rates without page reloads. API Communication: Secure communication with NOWPayments API endpoints for currency lists and rate calculations. Dynamic Updates: Real-time updates of estimated amounts when customers change their cryptocurrency selection. Error Handling: Comprehensive error handling for network issues, API failures, and invalid responses. Security: All API calls are made server-side to protect API keys and ensure secure communication. Important Notes for Customers: Exchange rates are calculated in real-time and may fluctuate during the payment process Payment amounts are locked once you proceed to the NOWPayments payment page Ensure you have sufficient cryptocurrency balance in your wallet before initiating payment Payment confirmations may take a few minutes depending on the selected cryptocurrency network Contact support if you experience any issues during the payment process