Created a sudoku on pygame, stuck with creating a function that allows player to insert value into selected grid

Question

Sudoku code

Created a sudoku board and uses a sudoku API to generate the skeleton numbers but having trouble selecting position on win to blit in value. Nothing is appearing on the win after entering value.

def insert():
    while True:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                sys.exit()
            if event.type == pygame.KEYDOWN:
                value = my_font.render(str(event.key), True, (255, 255, 255))
                win.blit(value, (pos[0], pos[1]))
                pygame.display.update()
while True:
    create_grid()
    import_num()
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        if event.type == pygame.MOUSEBUTTONDOWN and event.button == 1:
            pos = pygame.mouse.get_pos()
            print(pos[0], pos[1])

    pygame.display.update() ```