Unable to load view on my custom route

I created a custom route and then tried to load a view/template( .tpl ), but couldnt. I also tried rendering some basic html in handler function but nothing worked. How can i create a custom route and then show some html or maybe a view on it.

I am using OJS 3.3.0-6


this is an example route that i want to create

image


this is my handler code .