How to use Github Release Version Number in Github Action

It should be ${{ github.event.release.tag_name }}. The structure of a release can be found here: https://developer.github.com/v3/repos/releases/#get-a-single-release

I'd also suggest to use

on:
  release:
    types: [published]

instead of created to avoid putting something to npm for draft releases. See: https://help.github.com/en/actions/automating-your-workflow-with-github-actions/events-that-trigger-workflows#release-event-release

Hint:

To debug the event you can use:

jobs:
  debug:
    name: Debug
    runs-on: ubuntu-latest
    steps:
      - name: Dump env
        run: env | sort
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"

You can get tag version using ${{ github.event.release.tag_name }}.