This is a Windows PowerShell script for to convert MS Word documents to PDF files. You must have MS Word installed to run this script.

ConvertWordToPDF.ps1

## Source: https://techcommunity.microsoft.com/discussions/word/what-is-the-right-way-to-convert-word-to-pdf-in-bulk-on-a-pc-or-mac/4187546/replies/4187555
## Run the script:
## powershell -ExecutionPolicy Bypass -File "C:\Path\To\ConvertWordToPDF.ps1"
##

$word = New-Object -ComObject Word.Application
$word.Visible = $false

$folderPath = "C:\Path\To\Docs"
$outputFolderPath = "C:\Path\To\PDFs"

$files = Get-ChildItem -Path $folderPath -Filter *.docx

foreach ($file in $files) {
    $doc = $word.Documents.Open($file.FullName)
    $pdfFilename = [System.IO.Path]::ChangeExtension($file.Name, ".pdf")
    $outputPath = Join-Path -Path $outputFolderPath -ChildPath $pdfFilename
    #$doc.SaveAs([ref] $outputPath, [ref] 17) # 17 corresponds to the wdFormatPDF format
    $doc.SaveAs([String] $outputPath, [ref] 17) # 17 corresponds to the wdFormatPDF format

    $doc.Close()
}

$word.Quit()