Running WhatsApp on iOS 7.1.2 is no longer possible through official means, as support for this operating system officially ended in February 2020. While you can find legacy IPA files online, they are largely non-functional due to server-side blocks. The Reality of WhatsApp on iOS 7.1.2
Alternative: Use Telegram’s legacy version (Telegram 4.8.1 for iOS 7) or Signal if you must keep an old iPhone for messaging. WhatsApp’s forced obsolescence makes long-term use impossible. whatsapp ipa for ios 712 best
Before you rush to install that "whatsapp ipa for ios 712 best," read these warnings. WhatsApp has changed its policies. Running WhatsApp on iOS 7
Legacy Jailbreak Tweaks: Users in communities like r/LegacyJailbreak often discuss tweaks that can occasionally bypass "Update Required" pop-ups, but these rarely fix the underlying server-side connection issues for versions as old as iOS 7. Community Insights Messaging