Tistory not showing up well in Google search - SEO, sitemap, duplicate content

I'm a frequent contributor to the Tumblr blog. However, for several years, the number of T-story visitors has never exceeded three digits. I have KakaoAdFit and Tenping ad platforms on my Tstory blog, but my ad revenue is always close to zero due to the low number of visitors.
Recently, I was thinking about this problem and started looking for information about Google Search Engine Optimization (SEO).

First problem: Google Search Console sitemap

The first problem was the sitemap. We weren't submitting the right sitemap to Google Search Console. All you need to do is go to Google Search Console, enter sitemap.xml and submit.

Also, it looks like you can use the Google Index API to automate indexing requests to Google as soon as you publish a post to your Stories.

import Axios from "axios";

const INDEXING_API_URL = "https://indexing.googleapis.com/v3/urlNotifications:publish";

async function requestIndexing(url: string): Promise<void> {
  const requestBody = {
    type: "URL_UPDATED",
    url
  };

  try {
    await Axios.post(INDEXING_API_URL, requestBody, {
      headers: {
        "Content-Type": "application/json",
      },
    });
  } catch (error) {
    console.error(error);
  }
}

The second problem: duplicate content

The second problem is "duplicate content" (https://seo-marketing.co.kr/236). If the same article exists on both platforms, it will be ranked lower in Google search and will not be visible in Google search.

I wrote a post a few days ago, "Worries about publishing simultaneous posts on T-story and Steemit". I think it's because I'm posting the exact same post on Steemit as on T-story.

The article "(ChatGPT) Automating your blog with OpenAI" was published on Tstory first and then on Steemit a few minutes later. However, if you search for it on Google, you can see that only the Steemit post is displayed.

I asked ChatGPT to solve this problem.

ChatGPT told me to use the <link rel="canonical" href="http://www.example.com/original-page.html"> tag with a link to the original content.
However, we can't use the link tag in Steemit. So I looked to see if there was another way.

As ChatGPT suggested, I put a link to the original post at the bottom of the Steemit blog.

Result

A few days after I did this, I googled my post. Luckily, the T-story article was at the top of the list. I'll give it a few more days, but it seems to have worked.

I think this is probably the reason why I was rejected from Google AdSense.
In the future, I will always insert a link to the original article at the bottom when posting on Steemit.