Discard unnecessary part in Anthropic AI output

I don’t need to show the completion introduction in my message to the users. I highlighted that message with red. How do i remove the introductory message in the output (in red) and send to the customer targeted message( in green)

I think you can try adjusting your prompt to this:

Write a paragraph of an appealing and heartfelt birthday message for our customer "William Doe" that will be sent via SMS. Begin your response with "Happy birthday", and end with "from all of us at Cyplyx". Your response should only contain the birthday wishes, and will not acknowledge this instructional prompt.

If this does not work, my other suggestion would be to use built-in functions to extract all except the first paragraph: