终于找到答案了.

离我的我已经不远了贴在上面.虽然我的问题是我在生成API key的时候，google home云控制台默认打开了错误的项目.我一直使用错误的 API 密钥.

It wasn't too far from the one I had posted above. Although my problem is that when I generated an API key, the google home cloud console opened the wrong project by default. I had the wrong API key all along.