Retrieving Unit IDs via API

[fenixero]

I am creating new entries for a component through the API:
POST /api/translations/(string: project)/(string: component)/(string: language)/units/
This endpoint allows me to create new entries in the component's only for default language.
How can I post translations for a key without knowing the unit ID (for the other languages)?
Or how can I retrieve the IDs of all units associated with a key?

[nijel]

There is currently no direct way for this. Let's track this as #13186

As a workaround, you can use upload with a file containing the single string only. It will match by key which you've chosen when creating the string.