First of all you need to log in to the Streamlabs website and access the "All Widgets" section clicking on the button situated in the left side menu.
Now click on the widget you want to setup. If you're here because you need to setup the Social Media Roller Widget, I suggest you to edit the "Sponsor Banner" one.
Scroll to the bottom of the widget's settings until you see the option "Enable Custom HTML/CSS" and select Enable to enable it. Once the editor is loaded start importing the content of the files in the folder downloaded previously: just copy and paste the content of index.html file to the HTML tab, then the content of style.css file to the CSS tab and finally the content of script.js file to the JS tab.
If your folder contains the custom.json file follow the next steps, otherwise just click on the Save Settings button and you're done with the setup.
- Click on Add Custom Fields.
- Scroll down and click on Edit Custom Fields.
- Copy and paste the content of custom.json to the Custom Fields Editor tab.
- Click on Update and then Save Settings.
- Now you can start customizing your widget filling up the custom fields you've just created. PS. To save your edits click on Save Settings any time.