Create language locales in D8 I am attempting to create/enable the UI to allow users to create translations in D8, and I need to create locales (e.g. en-us, en-gb, en-ca for English, es-mx, es-es for Spanish, etc). I've gone through the directions I've been able to find, and I am not seeing where to add specific locales after adding the base languages (at admin/config/regional/language). Or in the Translate tab on content items. Where do I go to enable specific locales?
To use locales separately, each has to be added as a custom language.

/admin/config/regional/language/add
Choose Custom language.
Enter the locale that you want as the Language code.
Enter the Language name.