练习银行APP项目HTTP请求报错求助：TypeError问题

我正在开发首个练习用银行APP项目，发送HTTP请求时出现错误，具体报错信息如下：

TypeError: Cannot use 'in' operator to search for '1000' in undefined
at Object.register (C:\MEAN SEP22\Angular\BANK\Bankserver\services\dataServices.js:9:14)
at C:\MEAN SEP22\Angular\BANK\Bankserver\index.js:38:32
at Layer.handle [as handle_request] (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\layer.js:95:5)
at next (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\route.js:144:13)
at Route.dispatch (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\route.js:114:3)
at Layer.handle [as handle_request] (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\layer.js:95:5)
at C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\index.js:284:15
at Function.process_params (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\index.js:346:12)
at next (C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\express\lib\router\index.js:280:10)
at C:\MEAN SEP22\Angular\BANK\Bankserver\node_modules\body-parser\lib\read.js:137:5

相关截图：

这是我的第一个项目，完全不知道后续该如何处理，恳请大家提供帮助。

内容的提问来源于stack exchange，提问作者Abhijith A Kumar