Why are none of my pages indexed in the google search console after 3 months on Shopify?

Topic summary

Pages on a Shopify site remain unindexed in Google Search Console after ~3 months. The owner resubmitted the sitemap and tried manual indexing, but gets “URL is not in the property” (i.e., the URL isn’t part of the verified Search Console property).
An SEO is already working on backlinks, keyword fixes, and content, yet indexing has not begun. The owner suspects a setup issue; Shopify support only shared generic Google resources, and contacting Google hasn’t helped.
Current action: a participant requested the site’s domain name to investigate further. Status: unresolved; key open questions are whether the correct Search Console property is verified and whether the sitemap/URLs match the verified domain.

Summarized with AI on December 27. AI used: gpt-5.

I have resubmitted the sitemap successfully and I can’t even index the pages manually as the platform says that the URL is not in the property.

I have someone working on SEO creating backlinks, fixing keywords and content and yet I can’t get any of my pages indexed.

I moved to Shopify to have better SEO and I know that it takes time but it’s been 3 months and there is clearly an issue in my set up, but Shopify supports only sends me publicly available info from Google and tells me to chat with Google, but Google is a black hole.

What’s your domain name?