Some solutions can help you, depend of your configuration.
Have you Linux or Windows app service? .net app or not?
You have .Net core app for example, you can use the Kestrel Middleware to redirect some route.
The best solution is to use system middleware. If you are on windows App Service, it's IIS. You can change this with web.config file. web.config file act like .htaccess for apache. You can add rules to redirect some route on another, and attribute an HTTP redirect code for SEO.