Click on the "Make Payment" button and enter the amount you wish to pay towards your Membership account. You will receive a email confirmation from PayPal of your transaction. Keep that as your proof of payment.
You will see "DONATION SUMMARY" and "DONATE" button at checkout, disregard that title as you are making a PAYMENT towards your bill. All questions regarding your payment made can be addressed to Rotarian Jake Woo, or to your current club President.