@dp.message_handler(content_types=['new_chat_members'])
async def send_welcome(message: types.Message):
bot_obj = await bot.get_me()
bot_id = bot_obj.id
for chat_member in message.new_chat_members:
if chat_member.id == bot_id:
await message.reply("Hi!\nI'm EchoBot!\nPowered by aiogram.")