Thingsboard : How to send data from a device to respective device configured in the Thingsboard via HTTP curl?

Question

Please check the attached image. Thingsboard:Send data via HTTP

1. As Device 1 & 2 send their respective status messages to Pairing Device 1. This data contains respective device IDs.
2. Pairing Device receives this message and send it to Thingsboard server via HTTP. -- Currently requires to include access token of Pairing device in the HTTP url. Is that necessary?
3. Pairing device which is already created in Thingsabord should identify the device (Device 1 or 2) based on the device ID in the received message and update the attributes/telemetry data of respective device.

How to achieve 3rd point in the Thingsboard? What things needs to be done here to achieve it?