Swimbot Error

Traceback (most recent call last):
  File "C:\Users\wmiller.GTI\AppData\Local\Programs\Python\Python37\lib\site-packages\discord\ext\commands\core.py", line 85, in wrapped
    ret = await coro(*args, **kwargs)
  File "c:\Users\wmiller.GTI\OneDrive - Goddard Technologies\Desktop\SwimBot\Swimbot\whois.py", line 304, in whois
    embed.set_footer(text=f"Requested by {ctx.message.author.name}", icon_url= ctx.message.guild.get_member(ctx.message.author.id).avatar_url)
AttributeError: 'NoneType' object has no attribute 'avatar_url'