Yubikey integration

Hello,

I want to integrate the use of 2nd factor login using yubikey (USB dongle OTP). The use in wordpress is easy because there is a dedicated plugin. For now when a user register himself in standard registering page he can add his yubikey key number.
https://www.yubico.com/products/yubikey-hardware/

During the registration with ultimate member i want to add a field to allow the student to register his yubikey trough ultimate member plugin registration page. So i need a specific field for this. Have you any idea to achieve that?

Thanks for your help.

Massimo

https://www.ads-software.com/plugins/ultimate-member/