todo-txt-gnome-shell-extension | Gnome shell todo.txt extension

The preferred way is to use the Gnome extensions web page.
Obtain the source code, either by cloning the repository or by downloading a tarball from the GitLab page
Extract, copy or move the code to the directory ~/.local/share/gnome-shell/extensions/todo.txt@bart.libert.gmail.com Note: only this directory name will work, so pay attention
Make sure the following dependencies are installed on your system: glib-compile-schemas (In Debian, this is provided by the package libglib2.0-bin, check your distro's documentation for the correct package for your case) python The python modules mentioned in the file requirements.txt (If you use pip, you can do pip install -r requirements.txt). Note that additional requirements might be necessary for these. This depends on your system, so it's hard to provide a complete list (a web search engine like google or duckduckgo might help you if necessary), but some examples include: For debian testing: libxml2-dev, libxslt-dev, zlib1g-dev For Fedora 25: redhat-rpm-config
Run "make install"
Enable the extension with gnome-tweak-tool
Configure the extension with gnome-shell-extension-preferences