InvalidSelectValueError: Illegal select value 'None'.

[cervajs]

/home/someuser/pktai/.env/lib64/python3.13/site-packages/textual/widgets/_select.py:582 in _validate_value │
│ │
│ 579 │ │ │ # so we provide a helpful message to catch this mistake in case people didn' │
│ 580 │ │ │ # realise we use a special value to flag "no selection". │
│ 581 │ │ │ help_text = " Did you mean to use Select.clear()?" if value is None else "" │
│ ❱ 582 │ │ │ raise InvalidSelectValueError( │
│ 583 │ │ │ │ f"Illegal select value {value!r}." + help_text │
│ 584 │ │ │ ) │
│ 585 │
│ │
│ ╭─────────────── locals ────────────────╮ │
│ │ help_text = '' │ │
│ │ self = Select(id='model_select') │ │
│ │ value = 'None' │ │
│ ╰───────────────────────────────────────╯ │
╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
InvalidSelectValueError: Illegal select value 'None'.

fedora 42
python --version
Python 3.13.7

can you enable discussions in this repository?
is it possible use pktai with remote olama? how?