# Dynamic Updating

You can dynamically update the button via JS.

Use the js option to define the variable you want the button to be bound to:

{{ craft.webPayments.button({
	items: [{ id: 1, qty: 1 }],
	js: 'window.payButton',
}) }}

You can then get the current items and update them:

const items = [ ...window.payButton.items ];
items[0].options = { giftWrapped: 'yes' };
window.payButton.items = items;

You can't update the items directly (i.e. window.payButton.items[0].id = 2). The items are immutable, and therefore must be set to a new array if you want to update them. Above we are cloning the existing items into a new array before modifying them.

If you passed in a cart you can simply call refresh() to update the button with the latest contents of the cart.

window.payButton.refresh();

Note that you can't update the button while the payment dialog is active.

If you need to reload the button (i.e. if the DOM has changed) you can use the reload() function.

window.payButton = window.payButton.reload();

reload() will return a new instance of the button, so you'll want to replace your existing variable with that new instance.