async function accessing in another class giving blank response for object property how to solve this? [duplicate]

Question

I have two classes example1 and example2. example1 is having async method inside await keyword and promise response from API. When console inside async function am able to get print this.data and this.data but when I tried this to console inside example2 coming blank response where able to get response for this.key. How to solve this issue. This might be due to resolving promising taking time. Any suggestion ? below is sample example.

One class :

class example1{

constructor(){
  
 this.asyncFunction();
}

async asyncFunction(){
 this.key = await this.callAPI(url);

 this.data = await this.callAPI(url2);
}

callAPI(url) {
    const metadata = new Promise((resolve) => {
      fetch(url).then((res) => {
        const json = res.json();
        // console.log(json);
        resolve(json);
      });
    });
    return metadata;
  }
}

Second class :

import example1; // just added to show it imported class
class example2{

constructor(){
 const a = new example1();
 console(a); // i got all response; 
 console(a.data) // got blank response; 
}