啓動appium服務器後。我收到了這條消息。請告訴什麼地方出了錯 用法:main.js [-h] [-v] [--shell]啓動appium時出現錯誤信息
[--localizable-strings-dir LOCALIZABLESTRINGSDIR] [--app APP] [--ipa IPA] [-q] [-U UDID] [-a ADDRESS] [-p PORT] [-bp BOOTSTRAPPORT] [-k] [-r BACKENDRETRIES] [--session-override] [--full-reset] [--no-reset] [-l] [-lt LAUNCHTIMEOUT] [-g LOG] [--log-level {debug,info,warn,error}] [--log-timestamp] [--log-no-colors] [-G WEBHOOK] [--native-instruments-lib] [--app-pkg ANDROIDPACKAGE] [--app-activity ANDROIDACTIVITY] [--app-wait-package ANDROIDWAITPACKAGE] [--app-wait-activity ANDROIDWAITACTIVITY] [--android-coverage ANDROIDCOVERAGE] [--avd AVD] [--avd-args AVDARGS] [--device-ready-timeout ANDROIDDEVICEREADYTIMEOUT] [--safari] [--device-name DEVICENAME] [--platform-name PLATFORMNAME] [--platform-version PLATFORMVERSION]
main.js: error: argument "--app": Expected one argument. null