the previous responses was correct at the time but as of May 2025, Meta has updated their ad copy api to allow for the editing of "Top level creative parameters such as title, link_url, url_tags, body, and many others".

This is a huge improvement to the previous error-prone workflow of having to copy the entire adcreative when wanting to make a small edit to something like url_tags.

https://developers.facebook.com/blog/post/2025/05/28/you-can-now-change-creative-fields-when-duplicating-ads-with-ad-copies-api/
https://developers.facebook.com/docs/marketing-api/reference/adgroup/copies/#-creative-parameters-