WhatsApp will no longer work on these devices, backup chats like this

WhatsApp has FAQ section But WhatsApp has provided all the information about supporting devices. According to the Facebook-owned instant messenger, now WhatsApp will work only on those smartphones or other devices which are running on Android 4.1 or newer, iOS 10 or newer and KaiOS 2.5.0 or newer operating systems. There are only two options available for users working on older OS.
Users running smartphones older than Android 4.1, older than iOS 10, or older than KaiOS 2.5.0 will need to either update their smartphones to a newer version, or purchase a new mobile phone. Support has been discontinued as of November 1, 2021.
You can back up your WhatsApp chats on iCloud and restore them on a new device with the help of the steps given below.
To take a manual backup of your chats at any time, you have to go to ‘Settings’ of WhatsApp and tap on ‘Chats’ there. After this tap on ‘Chat Backup’ and tap on ‘Back Up Now’.