TextEncoder.prototype.encode()

b1 = encoder.encode(string);

<p class="source">This is a sample paragraph.</p>
<p class="result">Encoded result: </p>

const sourcePara = document.querySelector('.source');
const resultPara = document.querySelector('.result');
const string = sourcePara.textContent;

const textEncoder = new TextEncoder();

let encoded = textEncoder.encode(string);
resultPara.textContent += encoded;