Fonoma is an online service. Once registered, follow these steps to top your friend up.
From your computer (or phone 📲)
Access www.fonoma.com and log in with your Fonoma account username.
Type in the phone number you wish to recharge.
Choose the amount to recharge, paying in USD or EUR (the minimum purchase is the equivalent to 10 CUC and the maximum is 50 CUC).
Check the information for any mistakes before "Adding a payment method" as shown in the image.
Choose the payment method (credit card, debit card or PayPal) and type in the required information.
If you are paying with a card, you must fill out the following information:
Click on "Pay"