Changing the URL of Amazon S3 on a Dynamic Site

Is it possible to change the address of Amazon S3 to url starting with https://www.example.com/

S3 alone is not enough.You can customize the URL of the endpoint by placing other services in the first step.CloudFront is often used.(described later)

On static sites, it seems that it can be changed using CloudFront and Route 53.
Is there a way to change it on a dynamic site using Heroku?

I have no knowledge of Heroku, so I will answer from a general perspective.

When hosting web apps in the cloud, it is common to separate configurations between static and dynamic content.The following configurations may be considered for this time:

• Image (static content): CloudFront+S3
• Rails app (dynamic content):Heroku

In particular, you may want to add an alternate domain name www.example.com to CloudFront and refer to https://www.example.com/... from the Rails app hosted by Heroku.

Using Various Origins in CloudFront Distributions - Amazon CloudFront

Using Custom URLs by Adding Alternate Domain Names (CNAME)—Amazon CloudFront

There was a document that might be relevant in Heroku (Heroku seems to refer to static content as "static assets").

Using Amazon CloudFront CDN|Heroku Dev Center