Simple steps to use:
1.  Select a column of cells with text you want to analyze.
2.  Click the analyze button in the sidebar.
3.  Sentiment scores are output on a new sheet.

The analysis is performed by code running in the sidebar in your browser, instead of sending it to a cloud API for processing.  This means the add-on can provide you with unlimited processing at no cost.   Also, your text data never leaves the Google Sheets™️ environment.