mkdocs-material: Version selector missing

• I’ve read the contribution guidelines and agree with them

I’ve found a bug and checked that …

• … the problem doesn’t occur with the default MkDocs template
• … the problem is not in any of my customizations (CSS, JS, template)
• … the documentation does not mention anything about my problem
• … there are no open or closed issues that are related to my problem

Description

Hi there. I’m following https://github.com/squidfunk/mkdocs-material-example-versioning and it seems that I can’t create the version selector like stated in the doc.

Expected behavior

There should be a version selector.

Actual behavior

There is none.

Steps to reproduce the bug

pip install mike
git clone https://github.com/squidfunk/mkdocs-material-example-versioning.git`
cd mkdocs-material-example-versioning
mike deploy --update-aliases 0.1 latest
mike set-default latest
mike deploy --update-aliases 0.2 latest
mike serve
# or
mkdocs serve

Package versions

• Python: 3.9.1
• MkDocs: 1.1.2
• Material: 6.2.8

Project configuration

# Project information
site_name: My Docs
site_url: https://squidfunk.github.io/mkdocs-material-example-versioning/
site_author: Martin Donath

# Repository
repo_name: squidfunk/mkdocs-material-example-versioning
repo_url: https://github.com/squidfunk/mkdocs-material-example-versioning
edit_uri: ""

# Configuration
theme:
  name: material

# Customization
extra:
  version:
    method: mike

System information

• OS: Windows 10

• Browser: Chrome