Uncaught TypeError: get(...) is not a function

Running into an issue here where the following error is being thrown:

```
Uncaught TypeError: get(...) is not a function
at Class. (stripe-element.js:23)
```

Looks like `get(this, "stripev3.elements")` is returning undefined, so calling that function is blowing up. Any idea why this might be happening?

从 stripe-element.js:23 开始，追踪 get(this, "stripev3.elements") 在哪里初始化，以及在哪里执行了失败的调用。重现报告的 TypeError，并确认相关的 Stripe Elements 值在被调用之前可用；issue 中未指定测试或其他文件。

由索引模型根据 Issue 内容生成。