This is my js script. It only creates an anchor tag with text rather than a bulma button.
elementos.forEach(function(value,index){
var button = document.createElement("a");
button.class = "button is-primary is-rounded";
button.innerHTML = "Element " + (index +1)+ ": " + value
container.appendChild(button);
})
The problem is in your syntax.
This is the correct way to add a class to an element with Javascript:
button.classList.add("button is-primary is-rounded")