Select what you want to give towards and you'll receive a prompt on your phone to confirm the payment with your M-pesa PIN.
You can also plege to give regulary, whereby you'll receive an SMS reminder with a link that you can use to give based on the interval and amount you select.
"Each man should give what he has decided in his heart to give, not reluctantly or under compulsion, for God loves a cheerful giver."
- 2 Corinthians 9:7, NIV