How to add a release asset to give it a specific internal link

How to Use GitLab
1

I use docker to deploy gitlab-ce:12.10.1-ce.0.I create a release and add some assets to my release,like rpm packages and custom shell.I want to get a specific internal link to download the asset. e.g. https://gitlab.example.com/alauda/ovs/releases/download/v2.11.4-1/ovn-common-2.11.4-1.el7.x86_64.rpm

I refer to https://docs.gitlab.com/ee/user/project/releases/
Each asset has a name, a URL of the actual asset location, and optionally, a filepath parameter, which, if you specify it, will create a URL pointing to the asset for the Release. The format of the URL is:

https://host/namespace/project/releases/:release/downloads/:filepath

If you have an asset for the v11.9.0-rc2 release in the gitlab-org namespace and gitlab-runner project on gitlab.com , for example:

{
  "name": "linux amd64",
  "filepath": "/binaries/gitlab-runner-linux-amd64",
  "url": "https://gitlab-runner-downloads.s3.amazonaws.com/v11.9.0-rc2/binaries/gitlab-runner-linux-amd64"
}

This asset has a direct link of:

https://gitlab.com/gitlab-org/gitlab-runner/releases/v11.9.0-rc2/downloads/binaries/gitlab-runner-linux-amd64

I tried to specify the url by calling the release rest api,but failed.I guess the filepath is not configured correctly.It may be that the assert file is not stored in the specified path.
How to configure the filepath parameter here?