How to replace href when clicking on a link button?

Question

JavaScript

When you click on Buy, the text is replaced with Already in the cart.
How can I change the link to /cart/?

<script>
var about_bears = "Уже в корзине";
</script>

<a 
onclick="document.getElementById('<?=$arCurOffer['ID']?>').innerHTML = about_bears"
data-element-id="<?=$arCurOffer['ID']?>"
href="javascript:void(0);"
class="cartochka__btn-to-basket btn-black cartochka__btn-to-basket_contact-lens">
<div id="<?=$arCurOffer['ID']?>">Купить</div>
</a>

Answer 1

Google: "js change attribute value"
Response:
document.getElementsByTagName("a")[0].setAttribute("href", "/cart/");