I have a big web app. I am using pages router. the feature i wanna implement is multi tenant. been googling for hours but still no result. all nextjs multi tenant infos/tutorials/examples i have found are based on App router. i want https://my-app.com/users/slug to be https://slug.my-app.com/ with features like SEO. it should be dynamic and only work for dynamic datas like users, or companies. pages like about, policy should stay like https://my-app.com/about or /policy. today a backend dev told me to do this. or is it possible to do in the server like "masking" for example it https://slug.my-app.com/ under the hood uses https://my-app.com/users/slug ? Would appreciate your help...