<template id="my-template">
<div>
<input type="hidden" value="1" name="amount" />
</div>
</template>
You can set the id by querying for the div:
const deep = true;
const template = document.querySelector("#my-template");
const div = document.importNode(template.content, deep);
div.querySelector("div").id = "my-id";
document.body.appendChild(div);
Output:
<div id="my-id">
<input type="hidden" value="1" name="amount" />
</div>