Stderr: 'error: device unauthorized.

[xwSurfer]

I get "device unauthorized" when i running a sample code which is from appium website ,

appium client code :

// javascript
const wdio = require('webdriverio');

console.log("starting running test...");
// javascript
const opts = {
port: 4723,
desiredCapabilities: {
platformName: "Android",
platformVersion: "7.1.2",
deviceName: process.env.UDID,
// app: "/Users/david/work/xw/stf-appium-example/apks/android-sample-app.apk",
app: "/Users/david/work/xw/appium/files/demoApk/ApiDemos-debug.apk",
automationName: "UiAutomator2"
}
};

const client = wdio.remote(opts);

// javascript
client
.init()
.click("~App")
.click("~Alert Dialogs")
.back()
.back()
.end();

the command is :

DEVICE_SERIAL=b125680d7d04 ./scripts/run_integration_test.sh

appium log:

[debug] [BaseDriver] Creating session with MJSONWP desired capabilities: {"javascriptEnabled":true,"...
[BaseDriver] The following capabilities were provided, but are not recognized by appium: javascriptEnabled, locationContextEnabled, handlesAlerts, rotatable, requestOrigins.
[BaseDriver] Session created with session id: bc7c8cd7-f4be-4b7b-a839-70ccfed628d3
[BaseDriver] Using local app '/Users/david/work/xw/appium/files/demoApk/ApiDemos-debug.apk'
[debug] [UiAutomator2] Checking whether app is actually present
[debug] [AndroidDriver] Getting Java version
[AndroidDriver] Java version is: 1.8.0_92
[AndroidDriver] Retrieving device list
[debug] [ADB] Trying to find a connected android device
[debug] [ADB] Getting connected devices...
[debug] [ADB] 2 device(s) connected
[AndroidDriver] Looking for a device with Android '7.1.2'
[debug] [ADB] Setting device id to localhost:7401
[ADB] Getting device platform version
[debug] [ADB] Running '/Users/david/tools/Library/Android/sdk/platform-tools/adb -P 5037 -s localhost:7401 shell getprop ro.build.version.release'
[debug] [ADB] Running '/Users/david/tools/Library/Android/sdk/platform-tools/adb -P 5037 -s localhost:7401 shell getprop ro.build.version.release'
[debug] [UiAutomator2] Deleting UiAutomator2 session
[debug] [BaseDriver] Event 'newSessionStarted' logged at 1529116125651 (10:28:45 GMT+0800 (CST))
[MJSONWP] Encountered internal error running command: Error: Error getting device platform version. Original error: Error executing adbExec. Original error: 'Command '/Users/david/tools/Library/Android/sdk/platform-tools/adb -P 5037 -s localhost:7401 shell getprop ro.build.version.release' exited with code 1'; Stderr: 'error: device unauthorized.
[MJSONWP] This adb server's $ADB_VENDOR_KEYS is not set
[MJSONWP] Try 'adb kill-server' if that seems wrong.
[MJSONWP] Otherwise check for a confirmation dialog on your device.'; Code: '1'
[MJSONWP] at ADB.callee$0$0$ (/usr/local/lib/node_modules/appium/node_modules/appium-adb/lib/tools/adb-commands.js:89:11)
[MJSONWP] at tryCatch (/usr/local/lib/node_modules/appium/node_modules/babel-runtime/regenerator/runtime.js:67:40)
[MJSONWP] at GeneratorFunctionPrototype.invoke [as _invoke] (/usr/local/lib/node_modules/appium/node_modules/babel-runtime/regenerator/runtime.js:315:22)
[MJSONWP] at GeneratorFunctionPrototype.prototype.(anonymous function) [as throw] (/usr/local/lib/node_modules/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[MJSONWP] at GeneratorFunctionPrototype.invoke (/usr/local/lib/node_modules/appium/node_modules/babel-runtime/regenerator/runtime.js:136:37)