check who send a message discord/py code example
Example 1: send message discord.py
await message.channel.send("Your message")
Example 2: discord.py message user
if message.content == "dm":
await message.channel.send("Dming user")
dm = await message.author.create_dm() # Creates a dm channel with the user
await dm.send("What you want to send") # Sends the user the message