Download the firmware using the firmware ID (from the previous API call) and thing token.
MQTT Request
SUBSCRIBE v2/things/THING_TOKEN/firmwares/download/FIRMWARE_ID/response
PUBLISH v2/things/THING_TOKEN/firmwares/download/FIRMWARE_ID/request
# Subscribe for the response
mosquitto_sub -h "mqtt.thethings.io" -q 0 -t "v2/things/THING_TOKEN/firmwares/download/FIRMWARE_ID/response"
-d
# Publish request
mosquitto_pub -h "mqtt.thethings.io" -q 0 -t "v2/things/THING_TOKEN/firmwares/download/FIRMWARE_ID/request" -m '{"_requestId":"RAW"}' -d