I tried out the new Canvas with Chat GPT feature, it's really neat. I didn't think the code selecting and having GPT edit or explain something about it would work with a screen reader, but what you do is focus the multiline field with no label that pops up at the bottom of the page, and then you do text selection as normal. When you exit browse mode and move back into focus mode with #NVDASR you will be able to press an "ask GPT" button at the bottom of the page that appears. Quite nifty.