These are generally links to external sites (Github, Dropbox) to find materials
For the project in this area, this is the write-up describing requirements:
A place to look for country-level data, although individual statistical agencies might be superior. Even the OECD stuff (STAN, Supply/Use) needs care in identifying the right information that you need. Start with one year and one country, and see if you can get enough information to work with: