discord python bot error 400 Bad Request (error code: 50006): Cannot send an empty message

Question

simply i am making a discord bot and i got this problem :400 Bad Request (error code: 50006): Cannot send an empty message . and here is my code:

import os
import discord
import responses

async def send_message(message, user_message, is_private):
    try:
        response = responses.get_response(user_message)

        embed=discord.Embed(
          title='Bad words.',
          description='Do not say bad words again,please.',
          colour=discord.Colour.blue()
        )
      
        if response == 'Do not say bad words again,please': 
          await message.author.send(embed=embed)
        else:
          if is_private:
            await message.author.send(response)  
          else :
            await message.channel.send(response)

    except Exception as e:
        print(e)

def run_discord_bot():
    TOKEN = os.environ['TOKEN']
    intents = discord.Intents.default()
    intents.message_content = True
    client = discord.Client(intents=intents)

    @client.event
    async def on_ready():
        print(f'{client.user} is now running!')

    @client.event
    async def on_message(message):
        if message.author == client.user:
            return
        
        username = str(message.author)
        user_message = str(message.content)
        channel = str(message.channel)

        print(f'{username} said: "{user_message}" ({channel})')


        if user_message[0] == '/':
            user_message = user_message[1:]
            await send_message(message, user_message, is_private=True)
      
        else:
            await send_message(message, user_message, is_private=False)
        
    client.run(TOKEN)

code in my responses file:

import random 


badWords=("badword","very bad")


def get_response(message: str)  -> str:
     p_message = message.lower()

  
     if p_message == 'hi':
 
        return 'hi'

  
     if message == 'roll':

        return str(random.randint(1, 6))

  
     if p_message == '!help':

        return '`this is a help message.`'
  
     if p_message.find in badWords:

        return 'Do not say bad words again,please'

my problem is in the bad word system because i want it to direct message an embed to anyone who say bad words but it gives this error and i will be implementing the message deletion algorithm later