cur.execute("SELECT * FROM channals")
rows = cur.fetchall()
con.close()
board = InlineKeyboardBuilder()
    try:
        for row in rows:
            board.add(types.InlineKeyboardButton(text=f"{row[2]}", callback_data=f"chan:{row[0]}"))
            board.add(types.InlineKeyboardButton(text="➕Добавить канал➕", callback_data="channal_plus"))
            board.add(types.InlineKeyboardButton(text="➖Удалить канал➖", callback_data="channal_minus"))
            board.add(types.InlineKeyboardButton(text="↪️В начало↩️", callback_data="ok"))
            board.adjust(*[1] * len(rows), 2, 1)

like this