F5 APM 2FA with Google and Yubikey

There was a copy paste error, posting my question again:

I have enabled a 2FA using Google & Yubikey for my VPN connection on F5 APM and it works fine when I use yubico authenticator app along with yubikey to generate TOTP code but as soon as I use my Yubikey without yubico and tab the yubikey to send the code to login page it enters the long MODHEX random value.

Without yubico app using yubikey tab directly on login page MODHEX Code : cccccckfhejfblgbcdbvijcitevndjrdjneuugeikugr

Whereas yubico authenticator shows TOTP as : 865646

I have found this video on youtube https://www.youtube.com/watch?v=mFmx4TDWyD0&t=36s but not sure how to convert this MODHEX value to TOTP using IRULE. Any help would be really appreciated.