Python//Tkinter - How Do I Make a "Remember Me" Checkbutton?

I want to take the user input of two textboxes, write them to a .txt file, and then input the contents of that file back into the two textboxes automatically the next time the program is launched, SO LONG AS a checkbutton is checked.

Essentially, a "Remember Me" checkbox so the user does not need to re-type their login details every time they open the program.