Open a terminal on this folder.
Install the dependencies...
npm install
Wait for it to finish and then build the app...
npm build
After it's finished you can load the unpacked extension by opening the index.html in the Public folder with the browser.
This is not recommended as the app uses extensions functions to get top sites from the browser for example.
Open a terminal on this folder.
Install the dependencies...
npm install
Wait for it to finish and then run the app...
npm run dev
Navigate to localhost:5000. You should see the app running. You might see some errors on the console or that the app doesn't load, this is because the app uses extensions specific stuff like getting the Top Sites from the browser.