You must have an iPhone capable of running iOS 15.1 (e.g., iPhone 6s or newer) to use the official WhatsApp app. Potential Workarounds
Since "10.33" is not a standard public WhatsApp version number (current versions are in the 2.x range), I have prepared a post assuming you are looking for a or News post about WhatsApp working on older iOS versions (like iOS 10.3.3).
You may find older versions of WhatsApp on unofficial stores (like Jailbreak-related repositories), but these versions will eventually fail to connect to WhatsApp's servers because the protocols have changed. 💡 Recommendation
WhatsApp left Support for iPhone 5,5c iOS 10.3.4 | What Next ?
If you’d like, I can still write a on a likely related topic, such as: