I have the same question for WebAssembly: https://forum.qt.io/topic/155454/dealing-with-keyboard-layout-for-input-on-qt-webassembly

here is the solution: https://forum.qt.io/topic/76802/how-to-enable-virtual-keyboard-languages/5

Thank you all, I am going to mark this discussion as solved; However, Any more comments would be much appreciated;

I think MikePelton is long gone but nevertheless I would like to thank him for his contribution. I was caught out by this today. I always use the 'INS' on the numeric pad to toggle insert/overstrike - in other editors at least - so was a bit baffled as to how to get back to insert mode. As noted by Mike, the separate INSERT key does work.