How to use Openpyxl update cell value in excel after compare using Python?

Question

1. I have two different excel to compare...

                                 Data1.xlsx                                        Data2.xlsx
   |  Name   |   City    |  Reg Date  | Gender | Check In | Check In Date |  |   Name  |  Reg Date  |
   |Alex     | Hong Kong | 2021-06-30 | Male   |    Y     |  2021-06-30   |  |Annie    | 2021-07-01 |    
   |Annie    | Hong Kong | 2021-07-01 | Female |          |               |  |Billy    | 2021-07-02 |    
   |Bob      | Taipei    | 2021-06-28 | Male   |    Y     |  2021-06-28   |  |Cathrine | 2021-07-03 |    
   |Lucy     | Tokyo     | 2021-06-28 | Female |    Y     |  2021-06-28   |  |David    | 2021-07-04 |    
   |David    | London    | 2021-07-04 | Male   |          |               |  |Eric     | 2021-07-04 |    
   |Kate     | New York  | 2021-07-03 | Female |          |               |
   |Cathrine | London    | 2021-07-03 | Female |          |               |
   |Rose     | Hong Kong | 2021-07-04 | Female |          |               |
   

2. I get Name & Reg Date for key to merge

   import openpyxl as xl
   import pandas as pd
   import numpy as np
   
   dt1 = pd.read_excel('Data1.xlsx')
   dt2 = pd.read_excel('Data2.xlsx')
   df_merge = pd.merge(dt1, dt2[['Name', 'Reg Date']], on=['Name', 'Reg Date'], how='left', indicator=True)
   
      Name         City     Reg Date   Gender  Check In  Check In Date    _merge  
   0  Alex      Hong Kong  2021-06-30  Male       Y       2021-06-30    left_only     
   1  Annie     Hong Kong  2021-07-01  Female    NaN          NaN            both 
   2  Bob       Taipei     2021-06-28  Male       Y       2021-06-28    left_only    
   3  Lucy      Tokyo      2021-06-28  Female     Y       2021-06-28    left_only
   4  David     London     2021-07-04  Male      NaN          NaN            both 
   5  Kate      New York   2021-07-03  Female    NaN          NaN       left_only
   6  Cathrine  London     2021-07-03  Female    NaN          NaN            both
   7  Rose      Hong Kong  2021-07-04  Female    NaN          NaN       left_only
   

3. Q1: Is it possible to use openpyxl to update Check In & copy Reg Date to Check In Date base on df_merge value is both?

   wb = xl.load_workbook('Data1.xlsx')
   ws = wb.active
   for row, value in enumerate(df_merge, start=2):
   

4. Below is my expected results. Please anyone who can teach me?

                               Updated Data1.xlsx                                        
   |  Name   |   City    |  Reg Date  | Gender | Check In | Check In Date | 
   |Alex     | Hong Kong | 2021-06-30 | Male   |    Y     |  2021-06-30   | 
   |Annie    | Hong Kong | 2021-07-01 | Female |    Y     |  2021-07-01   | 
   |Bob      | Taipei    | 2021-06-28 | Male   |    Y     |  2021-06-28   |
   |Lucy     | Tokyo     | 2021-06-28 | Female |    Y     |  2021-06-28   |
   |David    | London    | 2021-07-04 | Male   |    Y     |  2021-07-04   | 
   |Kate     | New York  | 2021-07-03 | Female |          |               |
   |Cathrine | London    | 2021-07-03 | Female |    Y     |  2021-07-03   |
   |Rose     | Hong Kong | 2021-07-04 | Female |          |               |