save excel file stream to azure blob storage

The problem seems to be here: wb2.save(output), you can refer to the following code:

import logging
import azure.functions as func
import azure.storage.blob
import openpyxl as xl
import io
from tempfile import NamedTemporaryFile


def main(myblob: func.InputStream):
    logging.info(f"Python blob trigger function processed blob \n"
                 f"Name: {myblob.name}\n"
                 f"Blob Size: {myblob.length} bytes")
    #logging.info(myblob.read())
    logging.info('Loading Workbook...')
    ### Load Excel file
    wb1 = xl.load_workbook(filename=io.BytesIO(myblob.read()))
    ws1 = wb1.worksheets[0]
    logging.info(wb1.sheetnames)

    ### Create Second Workbook
    #output = io.BytesIO()
    wb2 = xl.Workbook()
    ws2 = wb2.create_sheet('TestSheet')

    # calculate total number of rows and 
    # columns in source excel file
    mr = ws1.max_row
    mc = ws1.max_column
    
    # copying the cell values from source 
    # excel file to destination excel file
    for i in range (1, mr + 1):
        for j in range (1, mc + 1):
            # reading cell value from source excel file
            c = ws1.cell(row = i, column = j)
    
            # writing the read value to destination excel file
            ws2.cell(row = i, column = j).value = c.value

    ### Upload to Azure Blob Storage
    conString = ""
    blob_service_client = azure.storage.blob.BlobServiceClient.from_connection_string(conString)
    blob_client = blob_service_client.get_blob_client(container='testout', blob='test2.xlsx')
    with NamedTemporaryFile() as tmp:
        wb2.save(tmp.name)
        output = io.BytesIO(tmp.read())
        blob_client.upload_blob(output)