I don't see it. With Chrome devtools, for the posted URL I see X-Clacks-Overhead, X-Content-Type-Options, and X-Frame-Options. No X-Robots-Rag.
And no <meta name="robots"> in the HTML either.
What URL are you seeing that on? And what tool are you using to detect that?
Edit: cURL similarly shows no such header for me:
curl -s -D - -o /dev/null https://journal.james-zhan.com/google-de-indexed-my-entire-bear-blog-and-i-dont-know-why/Sorry. I am an idiot. Checked the wrong url. Please ignore.
UPD: Sorry, never mind, I inspected a wrong response.