403 error

[arpyo]

I can't start mpsyt 0.2.8. This is on AntiX Linux (a Debian). I get the following error, which concludes with 403.
Welcome pointers. Thank you!

File "/usr/lib/python3/dist-packages/pafy/util.py", line 27, in call_gdata
data = g.opener.open(url).read().decode('utf-8')
File "/usr/lib/python3.7/urllib/request.py", line 531, in open
response = meth(req, response)
File "/usr/lib/python3.7/urllib/request.py", line 641, in http_response
'http', request, response, code, msg, hdrs)
File "/usr/lib/python3.7/urllib/request.py", line 569, in error
return self._call_chain(*args)
File "/usr/lib/python3.7/urllib/request.py", line 503, in _call_chain
result = func(*args)
File "/usr/lib/python3.7/urllib/request.py", line 649, in http_error_default
raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/bin/mpsyt", line 11, in
load_entry_point('mps-youtube==0.2.8', 'console_scripts', 'mpsyt')()
File "/usr/lib/python3/dist-packages/pkg_resources/init.py", line 489, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/lib/python3/dist-packages/pkg_resources/init.py", line 2793, in load_entry_point
return ep.load()
File "/usr/lib/python3/dist-packages/pkg_resources/init.py", line 2411, in load
return self.resolve()
File "/usr/lib/python3/dist-packages/pkg_resources/init.py", line 2417, in resolve
module = import(self.module_name, fromlist=['name'], level=0)
File "/usr/lib/python3/dist-packages/mps_youtube/init.py", line 8, in
init.init()
File "/usr/lib/python3/dist-packages/mps_youtube/init.py", line 59, in init
cache.load()
File "/usr/lib/python3/dist-packages/mps_youtube/cache.py", line 34, in load
pafy.load_cache(cached['pafy'])
File "/usr/lib/python3/dist-packages/pafy/pafy.py", line 182, in load_cache
set_categories(newcache.get('categories', {}))
File "/usr/lib/python3/dist-packages/pafy/pafy.py", line 169, in set_categories
catinfo = call_gdata('videoCategories', query)
File "/usr/lib/python3/dist-packages/pafy/util.py", line 35, in call_gdata
raise GdataError(errmsg)
pafy.util.GdataError: Youtube Error 403: The request cannot be completed because you have exceeded your quota.

[arpyo]

I removed the app, deleted the folder containing the cache and config, and reinstalled. Then I set my own API key. Up and running!