Back when I was running a fund and writing monthly reports @Slomo - I used this site: https://au.investing.com/indices/s-p-asx-200-accumulated-historical-data
...which now causes Norton 360 to block a pop-up and warn me that there was a risky site trying to access my computer, but still leaves the investing.com tab open, so I don't know what's going on there, however that one has daily data - and monthly too if you toggle the setting - in that case for the XJO TR (ASX 200 Total Return or Accumulation index), but also other indices. I'm sure there are other options out there also.
That site I've linked to has never caused me any problems and I've been using them for about 8 years, however I do occasionally get these "suspicious site blocked" warning messages now that I've upgraded my PC's OS to Win 11. The blocked site isn't "investing.com" - it's some pop-up that occurs after you open it. With Win 10 I was using a pop-up blocker which blocked all pop-up windows in the background without alerting me.
There are no sign-ups or fees with that site, and I don't accept any cookies from them either, as I don't like those tracker cookies.