How do I make an animated background in the game menu in pygame?

How to properly embed the executing code that creates an animated background in the game in the game menu loop, which is presented below, there is also a picture of this game menu.

import pygame
from pygame.sprite import Sprite
import sys

pygame.init()


class Flame(Sprite):

    def __init__(self, images, time_interval):
        super().__init__()
        self.images = [pygame.image.load(f'images/{i}.jpg') for i in range(1, 61)]
        self.image = self.images[0]
        self.time_interval = time_interval
        self.index = 0
        self.timer = 0
    
    def update(self, seconds):
    self.timer += seconds
        if self.timer >= self.time_interval:
            self.image = self.images[self.index]
            self.index = (self.index + 1) % len(self.images)
            self.timer = 0


def create_images():
    images = []
    for i in range(4):
        image = pygame.Surface((256, 256))
        images.append(image)
    return images


def main():
    images = create_images()
    a = Flame(images, 0.25)
    
# Main loop.
    while True:
    seconds = clock.tick(FPS) / 300.0
    
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        
    a.update(seconds)
    screen.fill((230, 230, 230))
    screen.blit(a.image, (0, 0))
    pygame.display.update()
    
    
if __name__ == '__main__':
    screen = pygame.display.set_mode((1920, 1080))
    clock = pygame.time.Clock()
    FPS = 60
    main()
    

The fragment of the game menu below is from the main code

class Menu:
    ## Покрытие False по-умолчанию
    hovered = False
    ## Инициализация строк меню
    def __init__(self, text, pos):
        self.text = text
        self.pos = pos
        self.set_rect()
        self.draw()
    ## Рисование и рендер
    def draw(self):
        self.set_rend()
        screen.blit(self.rend, self.rect)
    ## Сам рендер
    def set_rend(self):
        self.rend = menu_font.render(self.text, True, self.get_color())
    ## Указание цветов (Покрытый\Не покрытый)
    def get_color(self):
        if self.hovered:
            return (255, 255, 255)
        else:
            return (0, 255, 0)
    ## Рендер углов
    def set_rect(self):
        self.set_rend()
        self.rect = self.rend.get_rect()
        self.rect.topleft = self.pos
## Главное Меню
def mmenu():
    ## Пункты меню
    menus = [Menu("NEW GAME", (870, 605)),
             Menu("Help", (920, 655)),
             Menu("AUTORS", (890, 705)),
             Menu("EXIT", (920, 755))]
    begin = True
    screen.blit(mm, (0, 0))
    ## Рабочий цикл
    while begin:
        pygame.event.pump()
        ## Проверка пунктов меню
        for menu in menus:
            if menu.rect.collidepoint(pygame.mouse.get_pos()):
                menu.hovered = True
            else:
                menu.hovered = False
            menu.draw()
        pygame.display.flip()
        ## Создал практически с нуля
        for event in pygame.event.get():
            if event.type == pygame.MOUSEBUTTONDOWN:# and event.button == 1: ## Небольшая правка
                for menu in menus:
                    if menu.hovered and menu.text == "NEW GAME": 
                        print("NEW GAME?")
                        click.play()
                        novel()
                    elif menu.hovered and menu.text == "Help":
                        print("Help?")
                        click.play()
                        helps()
                    elif menu.hovered and menu.text == "AUTORS":
                        print("AUTORS?")
                        click.play()
                        authors()
                    elif menu.hovered and menu.text == "EXIT":
                        begin = False
                        click.play()
                        pygame.quit()
##Анимация меню: