ChirpStack ThingsBoard and telemetry timestamp

The devices periodically send telemetry. The time when the data was collected is different from the time when it was sent. The timestamp is passed in the packet along with the data. How do I pass this timestamp to the Things board? So that the data is stored in the database with this timestamp?

from Thingsboard doc
_In case your device is able to get the client-side timestamp, you can use following format:
{“ts”:1451649600512, “values”:{“key1”:“value1”, “key2”:“value2”}}