Email OTP Implementation using F5 APM

Hi All,

I am trying to implement the same solution which is OTP on Email. I am able to get OTP in the mail which is generated on the very first AD login screen, but the other login page where the OTP is to be verified is not coming up and the page is kind of stuck or blank there.

The access policy is as shown in the image above. The Input OTP is a login screen to verify the received OTP which is not showing up. The configuration of Input OTP is:

Please suggest what the possible issue can be. I am following the detailed guide to implement OTP from F5 resource https://support.f5.com/kb/en-us/products/big-ip_apm/manuals/product/apm-authentication-single-sign-on-11-5-0/18.html