Facebook user scraper returns no results

Hello, I have been using your package for the last two days for scrapping twitter and it worked very well!
now, I am trying to scrape facebook and it is apparently not working as smoothly. I get an empty output. Is that normal? I can't find help on the internet.

Here my code:

```python3
from snscrape.modules.facebook import FacebookUserScraper,FacebookCommunityScraper
scraper = FacebookUserScraper(username='muppets')
res = scraper.get_items()
list(res)
```

Output: `[]`

I am using python version 3.8.5
Thank you for your help.