- Open Google Chrome.
- Navigate to
chrome://extensions
in the address bar. - Ensure that the Developer mode toggle in the top right corner is enabled.
- Click the Load unpacked button at the top left corner of the page.
- In the dialog that appears, select the directory where your extension's files are located.
- Click Select Folder (or Open on some systems).
- Your extension should now appear in the list on the Chrome Extensions page.
- Open Gmail and open a message and a modal should appear
Make sure to fill the API keys and App ID with values, the program will run without an App ID but have a message on top mentioning that an App ID is required.