SAP Lumira 1.29 offers an Extension Manager to simplify the installation process of extensions.
This Extension Manager can be found under the menu item File → extensions.
In the Extension Manager click on Manual Installation and select the downloaded file graphomate_charts_free_1.4.xx-LM1.30.zip. The installation files are installed in the directory: C:\Users\<username>\.sapvi\extensions.
After restarting SAP Lumira you find the installed components under Chart Exensions the chart picker.