You can use videos and images stored in your Google Drive account on Switcher Studio. There are a few ways to this:
When logged into Switcher Studio on your device, click on + blue button in the Sources section.
Click on Video.
Click on Files/USB Drive.
In the menu, click on Locations on the top left corner, and ensure Google Drive is enabled as a location from which to choose. (You must have Google Drive downloaded on your device and be logged in for this to work)
In the Google Drive menu, use the search bar to look for your video.
Click on the video you want.
In the Video Properties menu, make any changes you want and click on Done.
The video will now appear as one of your sources. To play your video at any point, just click on it.
For more information refer to the Switcher Support Center article here: https://support.switcherstudio.com/en/articles/3746433-importing-assets-from-google-drive