How to pay for form 1436?

I wanted to add an additional applicant to my existing visa application. I understand that I have to fill FORM 1436. I don’t know how to pay for the additional applicant. When I go to ImmiAccount/My Payments, it’s giving me options to pay only for paper-based additional applicant, not online. And I have read somewhere in the HOMEAFFAIRS website not to pay using this paper-based service for online application. I uploaded the change of circumstances form one week back, and I haven’t received any response from the immigration. I don’t know how to proceed further. Kindly help me with this issue.

Case officer should contact you with the instructions to pay.