What is the mistake in this code?

Question

This is a GUI using designer pyqt5 the dialog box is opening but the pushbutton is not working and also code has no error but the button showing no response help me to do correctly.
https://code.sololearn.com/c0S7QPVWQfnF/?ref=app

Answer 1

Yes, Md. Shahriar Parvez have you worked on pyqt5?

Answer 2

from PyQt5.QtWidgets import QDialog, QApplication

Sololearn doesn't have these library pre-installed.