Since your domain is very niche, you have to do marketing as well as targeted sales. Have you reached out to potential customers and asking them to use your service?

Also please consider making this a B2B enterprise product. To do that the main thing you need to do is hide the price or put insanely high prices. like $999 per year per license and above. If you are hiding prices, put a button to contact the sales team, which could be your phone number to start with.

Also put some white papers and add a lengthy demo with your own voice with an actual project, like Wordpress being protected and ask them to contact your sales if they need to enable the protection in their software as well. The demo could be put behind a sales form to collect contact details.

And hide your technology details. They don't need to know how you do it. Just give instructions on how to put enable your validation. Since you don't have a free tier it's very easy for you to validate your project's success. Just reach out to X potential customers (it's very easy for you to figure out potential customers too) and ask them to try your product. Give a 6 months money back. I

p.s. A great sales article I found on HN this week: https://stripe.com/atlas/guides/ama-steli-efti