Inserting user and password with SQLITE/PYTHON

Working on a group program that has users and passwords. We are trying to insert our users and passwords via python to sqlite. But atm we are only sending blank data before our graphic window pops up with a button that is supposed to send the data. We have tried different variations found on multiple websites but nothing seems to work.

from tkinter import *
import sqlite3
import sys




conn = sqlite3.connect('indexCards.db')
cur = conn.cursor()
users ={}

def addUser(entUsername, entPassword):

    #global entUsername, entPassword
    NAME = entUsername.get()
    PASSWORD = entPassword.get()
    print("add User") #this is testing only
    print(NAME, PASSWORD) # this is testing to see the passed variable
    //
   //This is where we are having the issues
    conn.executemany('INSERT INTO USER(NAME,PASSWORD)\
          VALUES (? ,?);', [(NAME,PASSWORD)])
    conn.commit();

    return (NAME, PASSWORD)


def makeWindow():
    global entUsername, entPassword
    window = Tk()
    window.title('Add New User')

    lblInst = Label(window, text = "Create your account here:", font=("Helvetica",16))
    lblInst.pack()
    lblUsername = Label(window, text="Please enter a username: ")
    entUsername = Entry(window)
    lblUsername.pack()
    entUsername.pack()


    lblPassword = Label(window, text="Please enter a password: ")
    entPassword = Entry(window)

    lblPassword.pack()
    entPassword.pack()


    btn = Button(window, text="Create", command=addUser(entUsername, entPassword))

    btn.pack()
    print (addUser(entUsername, entPassword))
    print('entUsername', 'entPassword')

    #window.mainloop()

    return window



#if __name__ == '__main__':
 #   main():

window = makeWindow()
window.mainloop()