F5 Aws HA across Az , iapp ha question

Hello, I am following the official guide to deploy a cluster ha, across AZ whitout EIPs https://www.f5.com/pdf/deployment-guides/f5-aws-ha-dg.pdf, because there is a firewall that exposes the public IPs, and I have followed the next article https://devcentral.f5.com/s/articles/deploy-bigip-in-aws-with-ha-across-azs-without-using-eips-33378 where an alien segment is added and it is added to the route table associated to The nic of the active F5, but what is not clear to me is how the IAPP should be configured since the IApp obligatorily asks me for an elastic IP,

does anyone know how I can do if I do not have elastic IP how to deploy the active passive?