SHELL

typescript compiler

npm install -g typescript

tsc --init # creates a tsconfig.json file

tsc # transpile every file in the current directory
tsc index.ts # transpile a specific file
tsc --watch # transpile on change in current directory (watch changes)

run typescript compiler

npm install -g typescript
tsc --init #reate a tsconfig.json file
tsc --watch # transpile on change in current directory (watch changes)

# in your package.json "compilets-tojs": "npx tsc --project ./",
# you can rename "compilets-tojs" to any shorter name

npm run compilets-tojs

typerscript online compiler

Try this one:
https://www.typescriptlang.org/play/