Install it locally in your project folder:
npm i fastsc -D
# Or Yarn
yarn add fastsc --dev
# Or Pnpm
pnpm add fastsc -D
fastsc build
$ pnpm fastsc build
info - Clean output directories
info - Bundless for src directory to cjs format
event - Generate declaration file...
event - Transformed successfully in 176 ms (2 files)
✨ Done in 1.27s.
$ pnpm tsc
✨ Done in 2.59s.