input: Write a python function to generate responses based on specific keywords.
  assert respond("hello") == "Hi! How can I help you?"
  assert respond("What is your name?") == "My name is Chatbot!"
  assert respond("How are you?") == "I'm sorry, I don't understand. Could you try rephrasing that?"
output: def respond(input_text):
      if "hello" in input_text.lower():
          return "Hi! How can I help you?"
      elif "what is your name" in input_text.lower():
          return "My name is Chatbot!"
      else:
          return "I'm sorry, I don't understand. Could you try rephrasing that?"