Laravel 8 - inertia-jetstream-fortify, redirect to a particular URL before login (i.e. On hit of main URL ex.-www.something.com)

Question

I have a Single sign-in laravel application which is, say for example app-A. And my main application app-B. Now, whenever a user visits www.aap-B.com, I want the user to reach to the login page of app-A. Since app-B is built using laravel fortify whenever I first hit the site url of app-B it takes me to the login page of app-b. How to edit this login route in laravel since it is coming from vendor/laravel/fortify folder. How to make app-B follow the first endpoint to direct to URL of app-A without going to the defult login route when we hit the URl of app-B for the first time. I don't know where can I edit this login route in app-B. Any piece of advice would be of great help.