1. Go to your settings and click on Widgets. Once you opened your widgets settings, copy the widget URL of the widget you want to add to OBS.
2. Now open OBS and click on the plus icon in 'Sources' to add a new source.
3. Click on 'Browser' to add a browser source
4. Paste the URL you just copied into the URL section and click 'OK'.
5. Congratulations you have now successfully added a widget to OBS. If you want to test the widget, you can do this in your settings under 'Widgets'.