While it's possible to install WhatsApp on iOS 7.1.2 using an IPA file, it's essential to consider the potential security risks, compatibility issues, and lack of official support. Users should weigh the benefits of using WhatsApp on an older device against the potential drawbacks.
Moving to a device that supports at least iOS 12 is the only way to continue using WhatsApp. whatsapp ipa for ios 7.1.2
: On iOS 7.1.2, the app can no longer create new accounts or re-verify existing ones. While it's possible to install WhatsApp on iOS 7