WhatsApp will no longer be available on older versions of iPhones and Android smartphones with effect from February 1, 2020.
Users of phones running on Android versions 2.3.7 and older, and iPhones on iOS 8 or older will not be able to create new accounts or reverify existing accounts.
According to Techunzipped, one can find out which operating system their iPhone or Android uses:
To find out which operating system your iPhone uses, go to Settings, then General, then Software Update – your current version will be displayed there.
And if you use Android, you need to go to ‘Settings,’ then ‘About Phone’ and then ‘Software Info’.
Meanwhile, the development comes after WhatsApp discontinued supporting several devices on 31 December 2019.