The build commands I use are:
npm run build
npm run build:types
But this creates the following files inside ./dist

So I have to either rename the ossos.js manually into ossos.cjs.js or replace every mention of ossos.cjs.js into ossos.js inside package.json. After this step, I can successfully include them in my node project.
Below is the patch. Let me know if I do anything wrong, thank you.
801a3c.patch