How to change the default text and the function of OK and Cancel button in QInputDialog

I use this line in my code to pop up the QInputDialog and take input from the user.

But I want to change the button on this pop-up dialogue

def add(self):
    text, ok = QInputDialog.getText(self, " ", "Enter Value")

    if text == "" or text.isdigit() == False:
        print("Enter valid input")
        self.alert()
    else:
        print("ok value")
        self.ui.label_result.setText(str(text))

Using the static method QInputDialog::getText() it is difficult to modify the text of the buttons, so instead of using an object of that class and using the methods setOkButtonText() and setCancelButtonText():

def add(self):
    dialog = QInputDialog(self)
    dialog.setWindowTitle(" ")
    dialog.setLabelText("Enter Value")
    dialog.setOkButtonText("Foo")
    dialog.setCancelButtonText("Bar")
    if dialog.exec_() == QDialog.Accepted:
        text = dialog.textValue()
        if text == "" or not text.isdigit():
            print("Enter valid input")
            self.alert()
        else:
            print("ok value")
            self.ui.label_result.setText(str(text))
    else:
        print("canceled")