Go to WhatsApp → Settings → Chats → Chat Backup → Back up to Google Drive (or local storage).
WhatsApp has forced a server-side block on your specific build. Fix: You need to find a newer legacy APK. The WhatsApp team occasionally sunsets very old versions. Visit APKMirror and grab the most recent upload marked for Android 4.4.2. whatsapp apk for android 4.4.2
Below is a structured paper suitable for a short technical report or study note. Go to WhatsApp → Settings → Chats →