Can some help me out on how to pass the code test cases?

Question

I am new to coding so I decided to do the easy Code challenge (👽).. Was asked to produce mirror image. Below is my code but to my amusement, it's not passing the test case and I don't know where I went wrong. Keep getting syntax error :invalid character in identifier.
def myfunction(x):
  return x[::-1]

mytxt = myfunction(input() )

print (mytxt)

Answer 1

mytxt=myfunction(input())

Answer 2

#Maybe it's a problem with your keyboard.
#copy an paste this exact code

def myfunction(x):
return x[::-1]

mytxt=myfunction(input())

print(mytxt)

Answer 3

You have some invisible garbage character in your function name. Try deleting the whole 'myfunction' and type it again...

Answer 4

Did the correction but keeps showing the same error while it point to my function name. Changed the function name but the problem still persist.

Syntax error :invalid character in identifier