The Zillow application is portable, meaning that the $29 fee is a one-time fee and allows you to submit an application to as many participating landlords as you want for 30 days. To reuse the application within that 30-day period, you will need to log into the same Zillow account that was used to purchase the application.
If you paid for the application within the last 30 days, and are being prompted to pay again, this likely means you are logged into a different Zillow account. Please try logging out, and log back in with the email that you used when you purchased the application.
Once you have logged in, you can view your applications and screening reports from your Renter Hub.