It is a good idea to use async execution when sending data to an UbiFunction from external platforms like Particle.io or LoRaWAN Network Servers. This prevents failed or timed-out requests, which could affect server rating.
For instance, Particle skips webhook attempts when too many time-outs or 4xx / 5xx HTTP status codes occur, which could translate into data loss for your IoT application. Learn moreabout Particle's API Limits and Policy.
Not specified, or "False":
Not specified: By default the function will return a response only after finalizing the execution.
False: The function will immediately return a "202 Accepted" response, with a JSON body including the activationID of the function.