I had manually updated the site with the latest downloads from your site assuming the changes you made for php8 would be included. I now know that you hadn't updated those files in your official downloads. Thank you.
Now, there is an additional issue. None of the virutemart links work.
Try the "Shop by category" menu on the left side.
Try to search for a product.
https://modernmagic19.sg-host.com/
The last update is for VM 4.0.12 to 4.0.14, but apparently one meeds a Bronze membership with VM to get 4.0.14. The only .14 version I found is a quickstart including j3, which I obviously can't use. I doubt this is the reason the VM links are not working on my site but can you update to .14 ?