vue代理配置完运行项目报错，如何解决？

代理配置完运行时报错

module.exports = {
  devServer:{
    port:8888,
    host:'localhost',
    https:false,
    open:true,
    Proxy:{
      '/dev-api':{
        target:'http://localhost:8080',
        changOrigin:true,
        pathRewrite:{
          '^/dev-api':''
        }
      }
    }
  },
  lintOnSave:false,
  productionSourceMap:false
}

报错
ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
- options has an unknown property 'Proxy'. These properties are valid:
object { allowedHosts?, bonjour?, client?, compress?, devMiddleware?, headers?, historyApiFallback?, host?, hot?, http2?, https?, ipc?, liveReload?, magicHtml?, onAfterSetupMiddleware?, onBeforeSetupMiddleware?, onListening?, open?, port?, proxy?, server?, setupExitSignals?, setupMiddlewares?, static?, watchFiles?, webSocketServer? }

自己的练习，地址没错

Proxy是小写的proxy