How to change AppTitle and LoginTitle?

After installing Grafana successfully, I want to change AppTitle and LoginTitle, and I find thses two variables at public\app\core\components\Branding\Branding.tsx.
But after changing these variables, my page looks like no change.
So how to make it work?

Even this is an old post: this variable changes only take effect if you build the image from source. Adding them to a built grafana image wont do anything anymore.