Uploading to s3, with success callback on iOS

This question perhaps can be trivial, be as I am starting with IOS I'm not sure on what to search for.

I have a backend which handles processing of images, and with browser-based uploads, the images get upload directly to a temp folder in the app's bucket in S3, once done, I send the url to the backend for processing of the image in a background worker.

On IOS, I don't understand how and who is responsible for getting the url of the just-uploaded file to the server or to the app along with some meta data (which user uploaded the file, etc)

Looking at an S3 SDK for mobile example https://aws.amazon.com/articles/3002109349624271 I don't see that this is included.

Is that possible? Is that a common practice to do (get the url back from S3 and send it to the server along with meta data)?