Netlify doesn't appear to be adding canonica Link headers to requests

Netlify site name:
Custom domain:

I’ve just read through ​Improved SEO with canonical link headers, as I’m getting page indexing issues in Google Search Console.
I’ve used Postman to request my Netlify subdomain (which is set up to redirect to my custom domain), however I seem to get a 200 response code, and don’t see any Link headers in the response…

Is there something speific I need to do in order to get Netlify properly redirecting? I don’t have a canonical tag in my HTML

Netlify doesn’t modify your HTML. The canonical tag as added as a response header.

Thank you for your response. Please re-read my question, as I don’t talk about meta tags, I mention headers specifically

Hi @denno020 ,

We looked up your deployed redirect and see that you are redirecting the Netlify subdomain to your custom domain with a forced 301 and have confirmed that is the behavior when browsing to your site. We’re a bit confused about what you’re asking; are you asking about redirects not behaving as expected, or are you asking about SEO indexing?