I need to convert a non-nextjs page to nextjs. In order to not lose my SEO ranking, I have to create the route with html extension. To make the picture look better, I am adding the folder structure down below.

[![enter image description here](https://i.stack.imgur.com/zO1Bn.png)](https://i.stack.imgur.com/zO1Bn.png)

Unfortunately, this route ending up as 404 on the browser.

[![enter image description here](https://i.stack.imgur.com/iiUZy.png)](https://i.stack.imgur.com/iiUZy.png)

What is the problem? Am I allowed to use Next.js routes like that with html extension?