cssd-back/database/seeds/AccessSeeder.php

<?php

    use App\User;
    use Illuminate\Database\Seeder;
    use Spatie\Permission\Models\Permission;
    use Spatie\Permission\Models\Role;

    class AccessSeeder extends Seeder
    {
        /**
         * Run the database seeds.
         *
         * @return void
         */
        public function run()
        {
            if ( $this->assignAllRoleToAdministrator() ) {
                dump( 'Success.' );
            } else {
                dump( 'Error: Please Check And Run Again.' );
            }
        }

        private function assignAllRoleToAdministrator()
        {
            $roleModel = new Role();
            if ( $roleModel->where( 'name' , 'administrator' )->first() == null ) {
                Role::create( [
                    'name' => 'administrator'
                ] );
            }

            // assign role to user id 1
            $user = User::find( 1 );
            $user->assignRole( 'administrator' );

            // get all permission
            $permissions = [];
            foreach ( Permission::all() as $item ) {
                $permissions[ 'permissions' ][ $item ] = "1";
            }

            // assign all permissions to role administrator
            foreach ($permissions['permissions'] as $permission) {
                $role = Role::where('id', 1)->first();
                $role->syncPermissions(array_keys($permission));
            }
            return true;
        }
    }