download img from web and get base64 data

sample.html

<img/>

sample.js

  async function getBase64FromUrl(url) {
    const data = await fetch(url);
    const blob = await data.blob();

    return new Promise((resolve) => {
      const reader = new FileReader();

      reader.readAsDataURL(blob);
      reader.onloadend = () => {
        const base64data = reader.result;
        resolve(base64data);
      }
    });
  }

let url = "https://picsum.photos/200/300";

getBase64FromUrl(url)
.then(data => {  
  console.log(data);
  document.querySelector("img").src = data;
})