wx is not defined

yarn build 后，用百度开发者工具打开dist文件夹，提示wx is not defined
请问如何打包到百度小程序？或者说如何解决此问题？
注：wepy版本号为1.7.3

app.js:177 Uncaught ReferenceError: wx is not defined
at _default.$initAPI (app.js:177)
at _default.$init (app.js:92)
at Object.$createApp (base.js:110)
at app.js:167
at e (index.js:1)
at _wepylogs.js:3