Is there a way to implement CASAuthentication in a Nestjs app?

I want to dev a backend with NestJS on one of my company project.

I've to check if the user is logged through the CAS (Central Authentication Service).

I wanted to use "express-cas-authentication" npm module, but I can't find out how to implement it in the main.ts file from NestJS.

Here's the npmjs doc page : https://www.npmjs.com/package/express-cas-authentication

Actually, the following lines are annoying me :

app.get( '/app', cas.bounce, function ( req, res ) {
    res.send( '<html><body>Hello!</body></html>' );
});

It's not something that works on NestJS as I can see, if someone has a clue it'd be a great help!

Good evening Ladies and Sirs!