php - 字段中的触发事件不适用于 belongsToMany 关系字段

Question

我有以下字段

plan:
        label: Plan
        tab: account
        type: relation
        required: true
        placeholder: Select Plan
        emptyOption: No Plan Selected

    business:
        label: Select Business
        tab: account
        type: dropdown
        required: true
        placeholder: Select Business
        options: getBusinessOptions
        trigger:
            action: show
            field: plan
            condition: value[1]

对应的计划关系为

   public $belongsToMany = [
    'plan' =>[
        'MyPlugin\Plans\Models\Plans',
        'table' => 'cls_useraccount_subscription',
        'key'=>'user_id',
        'otherKey' => 'plan_id',
    ],
];

我只需要在 plan 为 1 时显示业务领域，但它与 belongsTo 计划关系一起工作正常，我需要让它与 belongsToMany 关系一起工作。

提前致谢。