According to the API documentation, and judging from the UI which includes a Browser/OS tab, it should be possible to transmit client information. However, the client field is completely missing from Rollbar\Payload\Data, suggesting this information is never sent and thus the feature is currently unavailable.
Rollbar UI

API docs

According to the API documentation, and judging from the UI which includes a Browser/OS tab, it should be possible to transmit client information. However, the
clientfield is completely missing fromRollbar\Payload\Data, suggesting this information is never sent and thus the feature is currently unavailable.Rollbar UI
API docs