How to configure DO Spaces With Subdomain?

I use do spaces on my site www.example.com without a subdomain. The setup looks like this:

DO_SPACES_KEY=key
DO_SPACES_SECRET=secret
DO_SPACES_ENDPOINT=https://fra1.digitaloceanspaces.com
DO_SPACES_REGION=fra1
DO_SPACES_BUCKET=bucketname

When uploading images everything works fine and images url looks like Bucketname.fra1.digitaloceanspaces.com/imagename

Now I found out that you can use subdomain on your space. I configured everything by creating cname on Cloudflare that points to the origin endpoint, installed the certificates from Cloudflare to DO and the subdomain endpoint was set like images.example.com

My question is how do I configure DO spaces to use this subdomain endpoint instead of the origin one? So I can be able to upload images to images.example.com instead of uploading to bucketname.fra1.digitaloceanspaces.com

Thanks.