I just write an article about a method to translate your Hugo website with no effort, no changes to your codebase and multiple languages translations in a few minutes. It’s called Weglot and they originally develop a Wordpress extension to translate websites.
The only thing you have to setup is a CNAME record subdomain for each languages you have. They also provide a custom language switcher you can customize.
You just have to follow my tutorial link : https://dev.to/louisbertin/ultimate-translation-method-for-static-website-generator-in-2020-hugo-4a24