You cannot add or replace a page in an issue you have already uploaded. 

The best way to add in your page is to prepare your PDF again with all of the pages in the correct order, and upload it as a new issue.

If you want to be able to add, remove and swap out pages in your issue, upgrade to the full Realview Publishing Suite.

Speak with your Realview Sales contact to learn more about the differences on RvRapid and Realview Premium, to see what suits your needs better.