Usermanager/Database/Seeders/UsersSeeder.php

<?php

    namespace Modules\Usermanager\Database\Seeders;

    use Faker\Generator;
    use Illuminate\Database\Seeder;
    use Illuminate\Support\Facades\Hash;
    use Modules\Usermanager\Entities\User;
    use Spatie\Permission\Models\Role;

    class UsersSeeder extends Seeder
    {
        /**
         * Run the database seeds.
         *
         * @return void
         */
        public function run(Generator $faker)
        {
            $roleAdmin = Role::find(1);
            $roleUser  = Role::find(2);

            $user = User::create([
                'name'              => $faker->name,
                'email'             => 'demo@demo.com',
                'password'          => Hash::make('demo'),
                'email_verified_at' => now(),
            ]);

            $admin = User::create([
                'name'              => $faker->name,
                'email'             => 'admin@demo.com',
                'password'          => Hash::make('demo'),
                'email_verified_at' => now(),
            ]);

            $admin->assignRole($roleAdmin,);
            $user->assignRole($roleUser);
        }
    }