我是新手，我正在尝试连接我的前端和后端，以便它可以接收和发送数据。但我好像不能让它工作。
这是launchsettings代码。json on backend：

{
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:56440",
      "sslPort": 44385
    }
  },
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "WebAPIv1._1": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "applicationUrl": "https://localhost:5001;http://localhost:5000"
    }
  }
}

而这是代理的代码。js in frontend：

const { createProxyMiddleware } = require("http-proxy-middleware");
import * as Path from "../Productivity/state/apiRoutes";

module.exports = app =>{
    app.use(
        createProxyMiddleware('/department',
        {
            target : 'https://localhost:44385/api',
            changeOrigin : true
        })
    )

}

我需要做什么才能让前端和后端都在ngrok上运行？
我尝试了通过打开ngrok连接前端和后端。yml并将里面的代码改为：

version: "2"
authtoken: 
tunnels:
    frontend:
        proto: http
        addr: 3000
    backend:
        proto: http
        addr: 44385

ngrok上的run ngrok start frontend backend。exe
我可以从ngrok打开前端URL，当我尝试登录到网站应用程序时会出现错误，因为它无法连接到后端，然后我从ngrok在后端URL上获得ERR_NGROK_3004。
感谢任何帮助！