Lighthouse GraphQL - How to return current_user in mutation resolver?

I have a situation where I'm writing a custom mutation resolver, and currently have to pass the current_user's ID from my frontend to be able to then perform a ::find on the User model. What would be ideal however, is to be able to use an instance of current_user so that I don't have to rely on passing over an ID to my GraphQL server.

I'm still fairly new to the world of Laravel and GraphQL in general, however I've been reading up on the Lighthouse docs that mention the @auth directive, and other StackOverflow answers that mention using auth('api')->user(), however that returns NULL for me. I should also mention that I'm using the lighthouse-graphql-passport-auth library for dealing with user authentication, if that makes any difference. Does anybody know how to access current_user?

public function __invoke($_, array $args)
    {
        // $user = \App\Models\User::find($args['id']); <--- not ideal
        $user = auth('api')->user(); <--- returns NULL
        var_dump($user);

        foreach ($user->notifications as $notification) {
            $notification->viewed = true;
            $notification->save();
        }

        $notifications = $user->notifications->toArray();

        return [
            'status' => 'Success',
            'notifications' => $notifications
        ];
    }

I found an interesting part in the lighthouse-graphql-passport-auth docs that discuss setting a global middleware to insert the logged in user into the $context. This was exactly like what I needed, and after adding the line into the middleware section of lighthouse.php config as mentioned in the docs, I was able to use $context->user() to return the currently logged in user.