It is.

https://sciactive.com/human-contribution-policy/#More-Information

Edit: since apparently no one actually follows this link, this is a link to a series of quotes that come directly from the United States Copyright Office that specifically apply to the question of whether AI generated code can be copyrighted. This is not an opinion piece, it is a series of direct quotes, which I share below.

In the Office’s view, it is well-established that copyright can protect only material that is the product of human creativity. Most fundamentally, the term “author,” which is used in both the Constitution and the Copyright Act, excludes non-humans.

– II. The Human Authorship Requirement

If a work’s traditional elements of authorship were produced by a machine, the work lacks human authorship and the Office will not register it. For example, when an AI technology receives solely a prompt from a human and produces complex written, visual, or musical works in response, the “traditional elements of authorship” are determined and executed by the technology—not the human user. Based on the Office’s understanding of the generative AI technologies currently available, users do not exercise ultimate creative control over how such systems interpret prompts and generate material.

– III. The Office’s Application of the Human Authorship Requirement

Some technologies allow users to provide iterative “feedback” by providing additional prompts to the machine. For example, the user may instruct the AI to revise the generated text to mention a topic or emphasize a particular point. While such instructions may give a user greater influence over the output, the AI technology is what determines how to implement those additional instructions.

– Footnote 30

(All from this document from the US Copyright Office: https://www.copyright.gov/ai/ai_policy_guidance.pdf)