sphinx-version-warning is a Sphinx extension that allows you to show a Warning banner at the top of your documentation.
By default, the banner is shown based on the version that is displayed compared (using SemVer) with the latest version on the server.
pip install sphinx-version-warning
Add this extension in your conf.py file as:
extensions = [
# ... other extensions here
'versionwarning.extension',
]Check out the full documentation at https://sphinx-version-warning.readthedocs.io/