How to use the kivymd.uix.button.MDFlatButton function in kivymd

def add_actions_buttons(self, box, data):
        if data:
            name_action_button, function_action_button = data
            action_button = MDFlatButton(
                text=f"[b]{name_action_button}[/b]",
                theme_text_color="Custom",
                text_color=self.theme_cls.primary_color,
                on_release=function_action_button,
            )
            action_button.markup = True
            box.add_widget(action_button)

_radius = NumericProperty(dp(2))
    _height = NumericProperty(dp(0))
    button_label = BooleanProperty(True)
    can_capitalize = BooleanProperty(True)


class MDIconButton(BaseRoundButton, BaseFlatButton, BasePressedButton):
    icon = StringProperty("checkbox-blank-circle")
    """Button icon."""


class MDFlatButton(BaseRectangularButton, BaseFlatButton, BasePressedButton):
    pass


class BaseFlatIconButton(MDFlatButton):
    icon = StringProperty("android")
    text = StringProperty("")
    button_label = BooleanProperty(False)


class MDRaisedButton(
    BaseRectangularButton,
    RectangularElevationBehavior,
    BaseRaisedButton,
    BasePressedButton,
):
    pass


class MDFloatingActionButton(
    BaseRoundButton, CircularElevationBehavior, BaseRaisedButton

def __init__(self, **kwargs):
        super().__init__(**kwargs)
        if self.button_text != "":
            button = MDFlatButton(text=self.button_text)
            self.ids.box.add_widget(button)
            if self.button_callback:
                button.bind(on_release=self.button_callback)

instance_content_dialog.ids.sep
                )

            box_buttons = AnchorLayout(
                anchor_x="right", size_hint_y=None, height=dp(30)
            )
            box = BoxLayout(size_hint_x=None, spacing=dp(5))
            box.bind(minimum_width=box.setter("width"))
            button_ok = MDRaisedButton(
                text=self.text_button_ok,
                on_release=lambda x: _events_callback(self.text_button_ok),
            )
            box.add_widget(button_ok)

            if self.text_button_cancel != "":
                button_cancel = MDFlatButton(
                    text=self.text_button_cancel,
                    theme_text_color="Custom",
                    text_color=self.theme_cls.primary_color,
                    on_release=lambda x: _events_callback(
                        self.text_button_cancel
                    ),
                )
                box.add_widget(button_cancel)

            box_buttons.add_widget(box)
            instance_content_dialog.ids.box_buttons.add_widget(box_buttons)
            instance_content_dialog.ids.box_buttons.height = button_ok.height
            instance_content_dialog.remove_widget(
                instance_content_dialog.ids.sep
            )

class MDRoundImageButton(MDFloatingActionButton):
    source = StringProperty()
    """Button image."""

    _current_button_color = [1, 1, 1, 1]

    def on_source(self, instance, value):
        self.source = value

    def on_size(self, instance, value):
        self.remove_widget(self.ids.lbl_txt)


class MDRectangleFlatButton(MDFlatButton):
    pass


class MDRoundFlatButton(MDFlatButton):
    _radius = NumericProperty(dp(18))

    def lay_canvas_instructions(self):
        with self.canvas.after:
            StencilPush()
            RoundedRectangle(
                size=self.size, pos=self.pos, radius=[self._radius]
            )
            StencilUse()
            self.col_instruction = Color(rgba=self.ripple_color)
            self.ellipse = Ellipse(
                size=(self.ripple_rad, self.ripple_rad),

"""Button image."""

    _current_button_color = [1, 1, 1, 1]

    def on_source(self, instance, value):
        self.source = value

    def on_size(self, instance, value):
        self.remove_widget(self.ids.lbl_txt)


class MDRectangleFlatButton(MDFlatButton):
    pass


class MDRoundFlatButton(MDFlatButton):
    _radius = NumericProperty(dp(18))

    def lay_canvas_instructions(self):
        with self.canvas.after:
            StencilPush()
            RoundedRectangle(
                size=self.size, pos=self.pos, radius=[self._radius]
            )
            StencilUse()
            self.col_instruction = Color(rgba=self.ripple_color)
            self.ellipse = Ellipse(
                size=(self.ripple_rad, self.ripple_rad),
                pos=(
                    self.ripple_pos[0] - self.ripple_rad / 2.0,
                    self.ripple_pos[1] - self.ripple_rad / 2.0,
                ),