In my limited web knowledge, I understand that in order to share information between different threads, you need to use "sharedarraybuffer." Unfortunately, this feature represents a potential security risk and can therefore only be used if the website has certain headers enabled to prevent these risks.

There is an admin post that discusses this, although it is focused on Godot, since web applications exported from Godot used multithreading. Unfortunately, I've read that this has caused several problems (for example, you can't have a downloadable version on the same page that has "sharedarraybuffer" enabled). The last thing I read was that people using Godot tried to use the latest version that allows exporting to the web in single thread instead of using multithreading and sharedarraybuffer.