WeChat Mini Programs"s wx.request is an asynchronous request. Perform background interaction in app.js onLaunch to obtain openid

APP({
    onLaunch:function(){
        //
        wx.login({
            success:res => {
                var code = res.code
                if(code){
                    wx.request({
                        url:xxx,
                        method:xxx,
                        success: res =>{
                            var that = this;
                            console.log("app.js---onLaunch")
                            that.globalData.openid = res.data.openid
                        }    
                    })
                }
            }
        })
    }
})

want to get openid in onReady phase in index.js

const app = getApp()

......

onReady:function(){
    console.log("index.js--onReady")
    console.log(app.globalData.openid)
}

the result is as follows

my goal is to get the openid on the index.js page and then do the this.setData ({}) assignment, but there is no value at this time because of asynchronism. I have tried several asynchronous methods, promise and cb. I just came into contact with javascript, but the train of thought is not very clear. is there an asynchronous callback?