maybe this will help you, walk you
or this, then you

beforeCreate this method is asynchronous, so the asynchronous operation on the other side of the created hook has not yet been assigned, so you can't get it in the created!
is it valuable to try for a delay of three seconds

listen for sd in subcomponents

// 
<template><component :sd="sd"></component></template>
// 
props:{sd: Array}  // 
watch:{
    sd: {
        immediate: true,  // sd
        handler(val, oldval){
            console.log(val)
        }
    }
}

whether the sd was empty during initialization, so the subcomponent reported an error. As a result, it cannot be rendered after a later re-assignment.