I've got a project build migrated from AOG + Dialogflow to Actions Builder. I need to update (or insert new) type entries with the REST API. To do that action I've found an endpoint, that gives the ability to update the whole project along with entities: https://developers.google.com/assistant/actions/api/reference/rest/v2/projects.draft/write
However, I can't connect to that endpoint due to 401 error. Before that I've tried to emulate a similar request to another endpoint, which allows reading the project:
https://developers.google.com/assistant/actions/api/reference/rest/v2/projects.draft/read
Obviously, I've got the same error here. Also, I've found this repo - https://github.com/actions-on-google/assistant-actions-nodejs which adds a wrapper for easier manipulation with the REST API, but it also doesn't contain any information on how to properly authorize to get access to an app.
Can please somebody suggest how authorization should be done to start using this REST API?