Lenovo OTP is a Lenovo "in-house" application, as apple's policy, you need to set trust list for the application in first-time use.
乐认证是联想内部使用的应用，根据苹果的策略，您在初次使用该应用时，需要将程序开发者加入到设备信任列表中。

Step1:click the "setting" button
第一步：找到您手机的“设置”按钮，点击进入设置

Step2:click the "General" button
第二步：找到“通用”，点击进入

Step3:click the "Device Management" button
第三步：找到“设备管理”，点击进入

Step4:Select the "Beijing Lenovo Software Co.,Ltd." button and trust the developer(If the pop-up prompt is inconsistent with the content below, please refer to the notes section at the end of the document.)
第四步：点击企业级应用下的“Beijing Lenovo Software Co.,Ltd.”，并在新页面中信任该开发者（如果弹出提示与下方不一致，请参考文档末尾注意部分）

Notes: Some users may need to restart their phones after trusting the developer. The specific steps are as follows:
注意：部分用户信任开发者后，可能需要重启手机。具体步骤如下:

Step 1: Allow apps from this "Beijing Lenovo Software Co., Ltd." to be opened on your iPhone and to access your data. Click “Allow & Restart” button
第一步: 允许来自"Beijing Lenovo Software Co., Ltd."开发者的 App在iPhone上打开并访问数据。点击“允许并重新启动”

Step 2: Swipe up to continue, then click the “Install Profile” button
第二步：重启后界面向上轻扫，弹出对话框选择“安装描述文件”