main.tt is loaded if I use a template at my code.
What is the reason main.tt is not loaded if I don't use a template?
For example, at following code, why main.tt is loaded at login page (get '/login') but not loaded at Home Page (get '/' )?

get '/' => sub { return "Home Page"; };
 
get '/login' => sub {
    # Display a login page; the original URL they requested is available as
    # param('requested_path'), so could be put in a hidden field in the form
template 'login', { path => param('requested_path') };
};

I could not find a logic explanation for it.

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