Google Slides embedded into Canvas are not easily read by any screen reader. Your best bet would be for the student to
1. Download the Google Read and Write extension
2. Open the options menu at the bottom of the slide deck (the gear)
3. Choose open editor
4. Then use the Google Read and Write extension to read the Google Slides
Google Chrome Read Aloud Extension
For quizzes in Canvas, you can highlight the text and right click to choose "Read aloud selected text" if you have this extension installed.
Google Speak It Chrome Extension