Starting point is the Bosch IoT Things HTTP API at our interactive API docs presence.
Authorize with the Suite Auth token
Open a new browser window at https://accounts.bosch-iot-suite.com/oauth2-clients/
Create a fresh bearer token and copy it to your clipboard
Navigate back to the Bosch IoT Things HTTP API description and apply it.
Click Try it out to get access to the entry fields
Specify the thing ID
Confirm with Execute.
you should be able to read the thing, otherwise re-check its policy.