Create asset for GitLab release

I am able to successfully create a release with the GitLab API but I am trying to create an additional asset that has a link in the release, package.zip. The release currently has the entire code as a zip but I am wanting to create a zip out of a subset of the repo.

Reading here: https://docs.gitlab.com/ee/user/project/releases/index.html#permanent-links-to-release-assets

It looks like I needed to do something similar to the following:

if __name__ == '__main__':
    url = "https://gitlab.com/api/v4/projects/12345678/releases"
    headers = {'PRIVATE-TOKEN': os.environ['CI_JOB_TOKEN']}
    data = {'tag_name': 'Lite-Release',
            'assets': {
                'links': [{
                    'name': 'link_test',
                    'url': 'https://gitlab.com/api/v4/projects/12345678/releases/Lite-Release/downloads',
                    'filepath': '/package.zip', 'link_type': 'other'}]
            }}
    post_resp = requests.post(url, headers=headers, data=data)
    print(post_resp.text)

This returns the error: {"error":"assets is invalid"} What am I missing here? Is the url field supposed to be what I want the url to be or what?

Edit: It does not appear to be a JSON formatting issue as the following works fine and creates a release.

if __name__ == '__main__':
    url = "https://gitlab.com/api/v4/projects/12345678/releases"
    headers = {'PRIVATE-TOKEN': os.environ['PRIVATE_TOKEN']}
    data = {'tag_name': 'tag_test', 'ref': 'HEAD'}
    post_resp = requests.post(url, headers=headers, data=data)
    print(post_resp.text)