Back-ticks in message show up literally

[shaperilio]

I'd like to send a message with a code fragment. So I tried this:

    - name: Send message
      if: always()
      uses: appleboy/discord-action@master
      with:
        webhook_id: ${{ secrets.DISCORD_ID }}
        webhook_token: ${{ secrets.DISCORD_TOKEN }}
        message: |
          Check out this code:
          ```python
          import os
          ```

But I see the three backticks in Discord, rather than import os formatted as code. How can I do this?