Store and then read ExcelFile

I need help with reading excel file from dcc.Store

request_file = requests.get(file_url, headers={'X-ACCOUNT-TOKEN': token_k})
url_data = request_file.content

if file_extension == 'csv':
    offer_file = pd.read_csv(io.BytesIO(url_data), sep=None, engine='python', keep_default_na=False)
    offer_file = pd.ExcelFile(io.BytesIO(url_data))

then i pass str(offer_file) to dcc.Store, and then i need to take it from store → get sheet_names from offer_file and generate dataframe

but i can’t… i don’t know what should i do for properly call pd.read_excel

i’v also tried to encode request_file.content with base64.b64encode - but got error messages:

TypeError: Object of type bytes is not JSON serializable

During handling of the above exception, another exception occurred:
raise exceptions.InvalidCallbackReturnValue(
dash.exceptions.InvalidCallbackReturnValue: The callback for `[<Output `filename.children`>, <Output `file_keeper.children`>]`
returned a value having type `tuple`
which is not JSON serializable.

The value in question is either the only value returned,
or is in the top level of the returned list,

and has string representation

In general, Dash properties can only be
dash components, strings, dictionaries, numbers, None,
or lists of those.

the solution was: