Use the API to add a record link between features/ideas and organizations

We’d like that once the organization is selected, an automatic Linked record would be created under the Related tab, showing a “relates to” for the relevant organization (adding it if not existed before).

First, I tried to find a way via rest API to add the linked Organization. But unfortunately I saw that the only types I can link are- feature, release, idea, epic, release phase, initiative, page, goal.