So ...

Upon activation, go to Media => Visualizer Library to access the page where all your charts will appear.

Click the "Add New" button to add your first chart.

A pop-up window will appear, where you can select the chart type you want to use:

Then click "Next" to continue.

A new window will appear where you can add your data source. The free version of the plugin will allow you to add data from a file or from a URL:

We are going to use a file, and we have two options: a CSV (Comma Separated Value) format or a simple plain TXT text file.

Any popular office aplication (Excel, Google Sheets, etc) will allow you to export your data spreadsheet as a CSV file, but the easiest way is to create a simple TXT text file in Notepad. Let's say that I want to create a pie chart with social media platforms and followers ... Here's my text file:

Note: the second row (string,numbers) defines the data type and can't be changed!

And all you have to do, is to click the "Browse" button, locate the TXT file on your computer and click "Import" ...

And here's the result in my case:

OK. Now let's see how can we display our brand new chart ...