Why are code snippets uncopyable when using "mkdocs build"?

Question

Why code snippets can be copied when running "mkdocs serve" with the mkdocs-material theme, but not when using "mkdocs build"?

Using mkdocs serve is resulting in:

Using mkdocs build there is no "copied" button:

How can I enable copying of code snippets in the static files generated by mkdocs build?

Answer 1

Refer: mkdocs-material docs

I found out that I wrote one less feature parameter in the latest version, as follow:

theme:
  name: material
  features:
    - announce.dismiss
    - content.action.edit
    - content.action.view
    - content.code.annotate
    - content.code.copy