How would you approach one page web app SEO optimization?

So I made this simple YouTube shorts downloader tool, it's basic static one page site that sends the call to the backend and that's it. There are a lot of these tools online but all of them look really scammy and they are filled with the ads, so I'm sure a lot of people would chose my project over those, BUT how can I optimize so I'm in the first few results. I guess it would be pretty difficult to do, but I would love to hear opinion. I've already left few comments with url in different subreddits under posts looking for such tool but not much other than that. Also almost whole text on the page is generated by AI, guess that can be improved? Edit: I guess I have good domain: ytshortsdl dot com (not sure if I can share urls here)