Why is Knitr Displaying R Code in the Output File

I would expect that the output HTML file would contain only the formatted header information. Instead, it displays the header information and, on the next line, ’’‘{r, echo = FALSE, results = FALSE} 1 + 2’’’.
What am I misunderstanding? How do I prevent the double-quoted text from appearing in the document?

title: "hide_test.rmd"
author: "Firstname Lastname"
date: "2022-07-28"
output: html_document

'''{r, echo = FALSE, results = FALSE}
1 + 2
'''

The wrong characters are being used to delimit the code chuck.
''' is used.