[Geschlossen] How to connect two languages via the WordPress REST API?

Background of the issue:
I use the WordPress REST API to create and update posts. For new posts, I refer to https://developer.wordpress.org/rest-api/reference/posts/#create-a-post and to update posts, I use https://developer.wordpress.org/rest-api/reference/posts/#update-a-post. Everything is working fine. I can create a German post and an English post and update both posts via the REST API.

Symptoms:
The only thing that is missing is how to connect both languages together via the API. It's like using the WPML option + to add another language post. I find no property in the API result that includes the post ID from the other post.

Questions:
How can I connect two languages via the WordPress REST API? If I do the connection manually, I don't find a property in the API result that includes the post ID from the other post.