Just did some (light) research and my memory was correct, this ability was kneecapped when Apple got rid of iTunes. iTunes used to be used to manage all updates and data on an iPhone (since iPhones originally came from iPods) but they never replaced some of its functionality when they made it obsolete.

It seems like it’s not entirely impossible currently, but you’d need the right files and the software which claims it would do it looks sketchy at best. I’m not going to investigate any further as it’s above my level of technical knowledge or desire. Hopefully there will be a solution or resolution so new users can experience zaps soon ⚡️