1. Install license-report (https://www.npmjs.com/package/license-report)

    npm install -g license-report

  2. run the script

    Get-ChildItem -Directory | foreach { $_ >> ./licenses.csv ; license-report --output=csv --only=prod --package=./$_/package.json >> ./licenses.csv }
    

You can use the same idea to run other stuff in subdirectories. Just replace the command. Here is an example of git pull.

Get-ChildItem -Directory -Force -Recurse *.git | ForEach-Object { cd $_.Parent.FullName; Write-Host $_.Parent.FullName; git pull }