Idgenerator laravel 8，如何修复异常"table field type is bigint but prefix is string"

为什么总是出现此消息？即使我想做一个有2个点的id，比如=190772.2021.00000001无法添加"。"(点(那样只能加1个点只有1907722021.0000001factory.php

namespace DatabaseFactories;
use AppModelsAnggota;
use IlluminateDatabaseEloquentFactoriesFactory;
use AppModelsUser;
use HaruncpiLaravelIdGeneratorIdGenerator;
class AnggotaFactory extends Factory
{
/**
* The name of the factory's corresponding model.
*
* @var string
*/
protected $model = Anggota::class;
/**
* Define the model's default state.
*
* @return array
*/
public function definition()
{
$tgl = $this->faker->date;
return [
'id_user' => User::factory(),
'no_anggota' => IdGenerator::generate([
'table' => 'anggotas', 
'length' => 19, 
'prefix' => date('dmy', strtotime($tgl)).date('.Y.')
]),
'nama_lengkap' => $this->faker->name,
'tempat_lahir' => $this->faker->cityPrefix,
'tanggal_lahir' => $tgl,
'nama_instansi' => $this->faker->word,
];
}
}

文件迁移

use IlluminateDatabaseMigrationsMigration;
use IlluminateDatabaseSchemaBlueprint;
use IlluminateSupportFacadesSchema;
class CreateAnggotasTable extends Migration
{
/**
* Run the migrations.
*
* @return void
*/
public function up()
{
Schema::create('anggotas', function (Blueprint $table) {
$table->id();
$table->unsignedBigInteger('id_user')->unique();
$table->string('no_anggota');
$table->string('nama_lengkap');
$table->string('tempat_lahir');
$table->date('tanggal_lahir');
$table->string('nama_instansi');
$table->timestamps();
});
}
/**
* Reverse the migrations.
*
* @return void
*/
public function down()
{
Schema::dropIfExists('anggotas');
}
}

而列"；no_anggota"在模式数据库中；字符串"；但是出现"；表字段类型为bigint，但前缀为字符串"；

如何解决它，使结果=190772.2021.00000001

帮帮我，谢谢