How to setup Specific Subdomain routing in Laravel | https://simplestweb.in/blog/how-to-setup-specific-subdomain-routing-in-laravel

.env

# Add the domain name of your choice
SITE_URL=myapp.com

hosts

127.0.0.1 laravel.test
127.0.0.1 admin.laravel.test
127.0.0.1 api.laravel.test

web.php

Route::middleware('web')->domain(env('SITE_URL'))->group(function() {
    # .... all your marketing website routes go here
});

Route::middleware('web')->domain('admin.' . env('SITE_URL'))->group(function() {
    # .... all admin portal routes go here
});

Route::middleware('api')->domain('api.' . env('SITE_URL'))->group(function() {
    # .... all api routes go here
});