Both are already there. Since May 2026 Shopify serves an llms.txt on every store by itself, and it has always kept your sitemap current. The question is no longer how to add them but whether what Shopify wrote says what you want it to.
Check yours first
Open yourdomain.com/llms.txt in a browser. On a store nobody has changed, it starts with # Agent Instructions and talks about the Shop app and something called the Universal Commerce Protocol. Then open yourdomain.com/sitemap.xml. Both load, so both checks pass, and there is nothing you have to do.
What Shopify’s llms.txt says, and what it does not
It is written for shopping assistants: how to search your products, build a cart and hand the customer to checkout. It is a copy of another file Shopify manages at /agents.md. What it does not do is describe your business: who you are, where you are, what you are known for and which pages answer the questions customers ask. That is what an llms.txt written for you would add, and the Fix Pack writes one from your own pages.
Replacing it with your own
Duplicate your theme. Online Store, then Themes, the three dots beside your live theme, then Duplicate.
Edit code on the theme you are changing.
In the templates folder, add a new file named
llms.txt.liquid. It has to be a Liquid file, not a JSON template.Paste the file in and save. Keep it plain text: in this template only a couple of Liquid objects work, so a shop name or a page list written in Liquid prints blank. Type the words in.
Publish the theme, then open
yourdomain.com/llms.txtand check it shows yours.
This replaces what Shopify serves at that address and nothing else. Shopping assistants still find their instructions at /agents.md, so you are not switching anything off.
Your sitemap
Shopify generates it at yourdomain.com/sitemap.xml and updates it as you add products, collections and pages. There is nothing to create and nothing to upload, so ignore the sitemap file in your Fix Pack. The first entry in it, sitemap_agentic_discovery.xml, is Shopify pointing assistants at /agents.md, and is expected.
If the finding mentions this check on a Shopify store, it is usually the other half of it: pages with no title or summary of their own. Where those are.
If your screens do not look like this, the wording has moved rather than the setting. Search your platform for the words in bold above. If you still cannot find it, send us the scan link and we will tell you where it is on your setup.