Problem with Submit button Tkinter

[balenaucigasa]

from tkinter import *

window = Tk()
window.title("Application de retraite")
window.geometry("640x640")
 
 
label1 = Label(window,text="Entrez votre nom: ",font=("arial",15,"bold"), fg="black").place(x=20, y=200)
i= StringVar()
entry_box1= Entry(window, textvariable=i, bg="gray", width="15").place(x=300,y=200)
 
 
label2= Label(window,text="Quelle est votre année de naissance?: ",font=("arial",15,"bold"), fg="black").place(x=20, y=300)
k= IntVar()
entry_box2= Entry(window, textvariable=k, bg="gray", width="15").place(x=300,y=300)
 
 
label3= Label(window,text="Quel est votre revenu mensuel sur vos vingt-cinq meilleures années ?: ",font=("arial",15,"bold"), fg="black").place(x=20, y=400)
revenu_moyen= IntVar()
entry_box3= Entry(window, textvariable=revenu_moyen, bg="gray", width="15").place(x=300,y=400)
 
 
label4= Label(window,text="Combien de trimestres avez vous cotisé ?: ",font=("arial",15,"bold"), fg="black").place(x=20, y=500)
trimestre_cotisés= IntVar()
entry_box4= Entry(window, textvariable=trimestre_cotisés, bg="gray", width="15").place(x=300,y=500)
 
 
label5= Label(window,text="Combien avez vous d'enfants ?: ",font=("arial",15,"bold"), fg="black").place(x=20, y=600)
enfants=IntVar()
entry_box5 = Entry(window, textvariable=enfants, bg="gray", width="15").place(x=300,y=600)

 
def do_it():
    print(i.get(), k.get(), revenu_moyen.get(), trimestre_cotisés.get(), enfants.get())

     
make_it = Button(window, text="PRINT", width="18", height="9",command=do_it,bg="lightblue").place(x=500, y=470)
     
window.mainloop()

you must use .get()