How to inject a script in html pages without touching the application code in ASP.NET Core

Question

I want to inject some Javascript code (which tracks total requests made from browser) in html responses in my ASP.NET Core application. I know that we can use middleware to manipulate the responses in ASP.NET Core. But I believe it requires changes in application code and redeployment. I want to do it without touching/modifying the application code, so that I can use it multiple applications. How can I achieve that?