No 2FA prompt after installation and enabled for an account (Umbraco 7.15.4)

[KevinHu-au]

Hi there,

I have followed the instructions to install the package on the Umbraco (7.15.4) back office.
The installation was fine, and I enabled the 2FA for an account.

But when I was trying to login with that account (after signed out), there was no Google 2FA prompt during the login process.
I have done the test on different accounts (and browser Incognito mode).

Not sure if I missed any thing.

Much appreciated!
Kevin Hu