Is it possible to call a function each time in tkinter?

Question

I have a following problem. I have a an entry field in my tkinter GUI where I write integer or character. I would like to click on the button and each time I click I would like to see if the input is integer or not. See my code:

import tkinter


root = tkinter.Tk()
root.geometry("600x500")

def command(number_rows):
    try:
        int(number_rows.get())
    except ValueError:
        print("Not an integer!")
    else:
        print("An integer!")

var_number_rows = tkinter.StringVar()

name_label = tkinter.Label(root, text="Number of rows:")
name_entry = tkinter.Entry(root, textvariable=var_number_rows)



button = tkinter.Button(
    root,
    text="Generate ",
    command=command(var_number_rows),
)

name_label.grid(row=0, column=0)
name_entry.grid(row=0, column=1)

button.grid(row=3, column=1)
root.mainloop()

However, when I click on the button in the GUI, nothing happens. Python gets "Not an integer!" when I run the script in the terminal, but not any more. How can I fix it, please?