Hello @Shivangi Thakur
Picking up from this post, I tried a few things but was unable to implement an 'if' conditional logic to display distinct footers using Ultimate PDF/ Simple Reports Reactive.
Given your urgency around this, I had an alternative suggestion.
The PDF Sharp asset in the Forge has server actions that you can use in a Reactive App. I have confirmed this. It allows you to merge multiple PDF documents into one document, and also allows you to append 1 page at a time to an existing document.
You could just create the PDF docs/pages with the footers of your choice and then merge/ append them in the right order. Tedious but possible. There is a catch - You won't be able to place page numbers on those docs as they will repeat over multiple documents since each document you append/merge will have its own Page 1,2,3 etc.
PDF Sharp (Extension name - PDF_Tools) comes with a sample application so you get an idea on how to use these actions 
If you do go this route, then the only difference from the Sample Traditional app and your own Reactive App would be => you would need to create a Server Action where for e.g. you merge the documents and then return the Binary output to a Client Action in your UI and then download the file in the Client action.
This is the best I could come up with, hope it is of some help to you,
Regards,
AJ