Go to this link https://core.telegram.org/api/obtaining_api_id and login with with the phone number regitered on telegram.
You will get the API ID and API HASH.
Run the python script and enter your api id, api hash and phone number(with country code).
Save the csv file in the same folder as this python script with the name "members.csv" (without quotes).
Enter the name of the csv file which contains all the members scraped.
It will show you names all the gropus in which you are a member.
Select the group in which you want to add the members and the script will do the rest.
You can either add members by username or by ID by selecting 1 or 2 respectively.