Infrastructure/Security/Authentication/AuthenticationService.php
public function getAdminHomeRouteForAdministrator(): string
    {
        if (array_key_exists($this->getAdministratorUsername(), $this->administratorHomeRoutes)) {
            return $this->administratorHomeRoutes[$this->getAdministratorUsername()];
        } elseif (null !== $roleRoute = $this->getAdminHomeRouteForAdministratorByRole()) {
            return $roleRoute;
        }
        
        // default
        return ROUTE_ADMIN_HOME_DEFAULT;
    }
public function getAdminHomeRouteForAdministrator(): string
    {
        if (array_key_exists($this->getAdministratorUsername(), $this->administratorHomeRoutes)) {
            return $this->administratorHomeRoutes[$this->getAdministratorUsername()];
        } elseif (null !== $roleRoute = $this->getAdminHomeRouteForAdministratorByRole()) {
            return $roleRoute;
        }
        
        // default
        return ROUTE_ADMIN_HOME_DEFAULT;
    }
determine home route: either by username, by role, or default