Recently, I have trying to use aws s3 upload provider I followed all the steps that article stated created a plugins.js file in config file but it resulted in Internal Server Error 500. After few searches on Google, I found a solution that created a settings.json inside a directory of extension/upload/config. Is that any thing I misunderstood about that article?
I’m guessing in your case you hit the beta documentation and not the stable release docs.
See: https://strapi.io/documentation/v3.x/plugins/upload.html#using-a-provider