Is it possible to update the content of my webpage by clicking a button without refreshing the URL?
Yes, it’s possible to update the page’s content without reloading it, and it is done through AJAX. This technique uses Javascript to perform these kinds of tasks. Considering shopify, there are specific APIs like Cart API, Product API, and Collection API that can help you achieve this.
I have done it number of times and here is my recent work for a client. Check it out whether this is what you need?