Upload slides, turn the camera on, and control the deck with your hand:
swipe → next, swipe ← previous, ✊ fist → read slide aloud.
PPTX isn't supported here (this is a static, backend-free page — nothing can
convert it to slides). Export your deck to PDF first
(PowerPoint/Keynote/Google Slides all have "Save as PDF" / "Download as PDF"),
then upload the PDF.