Can the the glass screen be replace

Let’s make sure we are on the same pages here.

This system came in two versions of displays the standard and the 4K. The given system you have can only support the display it came with! So a standard will only support a standard display and likewise the 4K model will only support the 4K display as the logic boards graphics is designed specifically for the given display.

So… If you have the 2017 model with the standard display thinking you could upgrade it that’s not possible!

If you have a 2019 system here is the needed part Apple P/N 661-12564 and LM215UH1(SD)(B1) or YH215UHD(SD)(A1) which is marked on the display.

Here’s one source BeetsTech 21” iMac 4K display assembly

And the guide to put it in Remplacement de l'écran de l'iMac Intel 21,5" Retina 4K 2019