Hi, Patricia Boyle,
I don't believe this feature is available within Slides at this time. That said, does the video have necessary audio? If not, have you thought about converting the video to a GIF and putting that in the presentation instead?
I suggest you provide feedback about this to the Google team, by doing the following:
- Open any document
- Click Help > Report an issue
- Enter your feature suggestion
- Hit Send
The product team is unable to respond to individual users' feedback; however, they do review all feedback regularly, and use it to help make improvements.
Hope this helps?