Thank you for kindly sharing your thoughts and suggestions Profiler..
No, they did not mention any address where to possibly send a copy of the payment receipt BUT stated in the letter to bring the receipt once appointment has been given... So, I just want to clarify and make sure if does that mean CIC will send or provide an appointment even if in case RPRF has not been paid yet?
And I just want to make sure that after paying the fee online, I don't have to do anything but wait for the appointment to be scheduled by CIC.
I will also take your suggestion by sending a PDF copy of the receipt to case specific inquiry.. Thank you for providing me the link.