Unfortunally the script stopped working for me few days ago :/
Thats the output from 403 Branch:

File "Python\Python311\Lib\site-packages\requests\models.py", line 971, in json
return complexjson.loads(self.text, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "Python\Python311\Lib\json_init_.py", line 346, in loads
return _default_decoder.decode(s)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "Python\Python311\Lib\json\decoder.py", line 337, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

File "Python\Python311\Lib\json\decoder.py", line 355, in raw_decode

raise JSONDecodeError("Expecting value", s, err.value) from None

json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

During handling of the above exception, another exception occurred:

File "rewe_discounts.py", line 194, in
data = scraper.get(url).json()
^^^^^^^^^^^^^^^^^^^^^^^
File "Python\Python311\Lib\site-packages\requests\models.py", line 975, in json
raise RequestsJSONDecodeError(e.msg, e.doc, e.pos)
requests.exceptions.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
FAIL: Unknown error while fetching discounts from https://mobile-api.rewe.de/api/v3/all-offers?marketCode=562286, maybe a typo or the server rejected the request.

Upon opening the link https://mobile-api.rewe.de/api/v3/all-offers?marketCode=562286 manuelly inside my browser it works just fine. Rewe must have improved their IT Skills recently😁
Doesnt necessarily look like an IP block for me.
I've been using the script for a relatively long time, really great work, too bad it doesn't work for me now.