I build my slides using marp. See the marpit reference for syntax guidance.
To develop slides, use
npm install
npx @marp-team/marp-cli@latest -s ./
To export slides, use
# Convert slide deck into HTML
npx @marp-team/marp-cli@latest slide-deck.md
npx @marp-team/marp-cli@latest slide-deck.md -o output.html
# Convert slide deck into PDF
npx @marp-team/marp-cli@latest slide-deck.md --pdf
npx @marp-team/marp-cli@latest slide-deck.md -o output.pdf
# Convert slide deck into PowerPoint document (PPTX)
npx @marp-team/marp-cli@latest slide-deck.md --pptx
npx @marp-team/marp-cli@latest slide-deck.md -o output.pptx