switch DB before auth in laravel - php

Question

I am building an application, where there would be main application users (say support users) and separate client users (the application can have many different clients and each clients can have many users), every client has its own separate database, but the codebase for the entire application would be the same for every client.
What I wanted to achieve is, before calling auth in the main application, I wanted to call a middleware, which would detect a parameter (say db_slug) from request URL and according to that param it will change the DB respectively. And then login them to the client user to their respective DB.
Note: The client users will not be a part of the main DB. Their record would be only in their Client's DB.
But I am failing to do so, as my auth middleware is called first, before my custom middleware, and on accessing auth routes, it is saying unauthenticated, since that specific client user is not a part of my main application.
Note: I am using sanctum auth.
What I tried is, created a middleware called ClientDBMiddleware
namespace App\Http\Middleware;
use Closure;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
use DB;
use Config;
class ClientDBMiddleware
{
/**
* Handle an incoming request.
*
* #param \Illuminate\Http\Request $request
* #param \Closure $next
* #return mixed
*/
public function handle(Request $request, Closure $next)
{
if($request->has('db_slug')){
$dbSlug = $request->db_slug;
DB::purge('mysql');
Config::set('database.connections.mysql.database', "db_$dbSlug");
}
return $next($request);
}
}
and applied it my api.php auth routes before auth middleware
Route::group(['middleware' => ['clientDB', 'auth:sanctum']], function () {
Route::get('/me', [UserController::class, 'me']);
});
Important Note :
If there is a better approach to achieve my required thing, then that would be highly appreciated, please help me with it.