How to make the bot make a mention(@username) that sent, for example, a command (more details in the details of the question)?

Question

Bots

Here is an example:
@Jack: /start
@bot: Hello @jack!
so that the bot mentions the person who wrote the command / message
Library: Telebot or you can Aiogram Yap
: Python

Answer 1

@dp.message_handler(commands="testing")
async def cmd_testing(message: types.Message):
    await message.answer(f'@{message.from_user.username}')