If you cannot run Minecraft 1.16.5 on your 32-bit PC, consider lightweight alternatives: (open source), Classicube (Minecraft Classic revival), or upgrading to a 64-bit system (even an old $50 used PC from 2012+ supports 64-bit).
It must be placed inside the .minecraft/versions/1.16.5/ folder and launched via the official launcher with the right Java.
It looks like you're looking for a linked to the code 11951 .