WhatsApp Business API测试号码突发报错：Cloud API中账户不存在求助

此前可正常使用测试号码通过Meta Cloud API发送消息到个人手机，从昨日下午起持续触发报错：

"Failed to send message. The account does not exist in the Cloud API. Use the /register API to create an account first."

通过Postman发起请求时，返回的错误响应如下：

"error": {
    "message": "The account is not registered",
    "type": "OAuthException",
    "code": 133010,
    "error_subcode": 2593006,
    "is_transient": false,
    "error_user_title": "The account does not exist",
    "error_user_msg": "The account does not exist in the Cloud API. Use /register API to create an account first.",
    "fbtrace_id": "A6fN7xoCSrj2t1dW_Qvv5d0"
}

VSCode的Flutter项目调试控制台也输出类似报错：

"flutter: {error: {message: The account is not registered, type: OAuthException, code: 133010, error_subcode: 2593006, is_transient: false,..."

已尝试以下操作但未解决问题：

• 检查所有API配置项
• 更换接收测试号码
• 查阅官方文档
• 搜索同类问题

恳请协助恢复测试功能。

内容的提问来源于stack exchange，提问作者Matheus Souza