| `id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) owned by the authenticated user |
| `issue_iid` | integer | yes | The internal ID of a project's issue |
| `target_project_id` | integer/string | yes | The ID or [URL-encoded path of the project](README.md#namespaced-path-encoding) of a target project |
| `target_issue_iid` | integer/string | yes | The internal ID of a target project's issue |
| `link_type`| string | no | The type of the relation ("relates_to", "blocks", "is_blocked_by"), defaults to "relates_to"). |
| `target_issue_iid`| integer/string | yes | The internal ID of a target project's issue |
| `link_type` | string | no | The type of the relation ("relates_to", "blocks", "is_blocked_by"), defaults to "relates_to"). |
```shell
curl --request POST --header"PRIVATE-TOKEN: <your_access_token>""https://gitlab.example.com/api/v4/projects/4/issues/1/links?target_project_id=5&target_issue_iid=1"
| `admin_notification_email` | string | no | Deprecated: Use `abuse_notification_email` instead. If set, [abuse reports](../user/admin_area/abuse_reports.md) are sent to this address. Abuse reports are always available in the Admin Area. |
| `abuse_notification_email` | string | no | If set, [abuse reports](../user/admin_area/abuse_reports.md) are sent to this address. Abuse reports are always available in the Admin Area. |
| `after_sign_out_path` | string | no | Where to redirect users after logout. |