Desktop CSV Automation Script

I need a small desktop-side automation that logs in to a specific website (standard username / password), navigates through the usual button sequence, downloads the available CSV file, fills the supplier name in its designated field, then uploads the related invoice—completing the entire loop without manual intervention. The flow must run reliably on a Windows machine.

You’ll receive:
• the site URL and working credentials
• a sample invoice file and the exact supplier name format expected

What I expect back:
• a runnable script or packaged RPA bot (Python + Selenium, Playwright, AutoHotkey, Power Automate Desktop—your choice, as long as it is lightweight and open for me to edit)
• clear setup notes and a quick walkthrough video or screenshots
• basic error handling—failed login, missing file, or field-validation issues should be reported to a log or message box
• parameters for supplier name and invoice path exposed in a config file so I can tweak without touching code

Once I can run the script end-to-end on my PC and see the CSV pulled, form completed, and invoice uploaded, we’re done.