Automated Facebook Group Poster

I need a lightweight tool that will let me publish the same image-based post to a small set of Facebook groups—no more than five—and then automatically repeat that post every five minutes without any manual input.

Here’s what matters to me:
• Image posts only. The tool should let me choose a single picture, write a short caption, and have that identical content cycle on schedule.
• A fixed 5-minute interval between repeats. I should be able to start or stop the loop at any time.
• Support for up to five groups. A simple way to paste in the group URLs or IDs once and store them securely is fine.
• Smooth, Facebook-friendly operation. Whether you rely on the official Graph API, browser automation (e.g., Selenium, Puppeteer), or a compact desktop script, the solution must respect Facebook’s limits so my account stays safe.
• Minimal setup. After you hand over the finished script/app, I’d like a quick walkthrough or short read-me so I can launch it on my own machine whenever I need.

Deliverables:
1. Source code or executable for the posting tool
2. Setup guide and basic usage instructions
3. A brief note on any required dependencies or API keys

If you’ve built something similar or know a reliable method to loop image posts this fast, let’s get it running.