The test you found is only to validate the JavaScript code of the application’s Decoder, and its results are only displayed, not handled in any way. Uplinks are sent through a device, not the application.
To test an uplink, add a (dummy) device to your application in TTN Console, and scroll down on its Device Overview page. You’ll see Simulate Uplink:
This simulated uplink will always have frame counter 0, but will be accepted no matter what: frame counter security violations are simply ignored. (In fact, at this point in the processing chain, no LoRaWAN frame counter checks are done at all; frame counter security is handled by the broker, which is not involved when injecting test application payloads.)
Below, the 07:42:35 and 07:42:48 uplinks on port 4 have been simulated for an existing device, but all others are true uplinks (and an OTAA Join) by the actual hardware:
I assume this also works for OTAA devices that have never even joined.
The simulated uplink is also run through the (optional) Decoder in the application’s Payload Formats, and forwarded through the MQTT API and the (optional) Integrations, including the HTTP Integration and the Data Storage Integration. The downlinks in the screenshot have been scheduled by a Pipedream workflow triggered by the HTTP Integration. For a simulated uplink such scheduled downlinks will be transmitted after a next real uplink.
Note that the details in the MQTT API and HTTP Integration are very limited, especially lacking metadata such as frequency, data rate and any details of the gateway(s). The HTTP Integration payload for a simulated uplink:
{
"app_id": "arjanvanb-app-ttnode",
"dev_id": "arjanvanb-ttnode-1",
"hardware_serial": "0004A30B001C1D1E",
"port": 4,
"counter": 0,
"payload_raw": "EqAAFAjE",
"payload_fields": {
"battery": 4768,
"event": "button",
"light": 20,
"temperature": 22.44
},
"metadata": {
"time": "2020-05-26T05:42:35.045417629Z"
},
"downlink_url": "https://integrations.thethingsnetwork.org/ttn-eu/api/v2/down/arjanvanb-app-ttnode/arjanvanb-http-ttnnode?key=ttn-account-v2.kFd<redacted>Vi_il4"
}
For reference, the HTTP Integration payload for a true uplink received by just a single gateway:
{
"app_id": "arjanvanb-app-ttnode",
"dev_id": "arjanvanb-ttnode-1",
"hardware_serial": "0004A30B001C1D1E",
"port": 3,
"counter": 2,
"payload_raw": "EqAAFAkJ",
"payload_fields": {
"battery": 4768,
"event": "motion",
"light": 20,
"temperature": 23.13
},
"metadata": {
"time": "2020-05-26T05:42:42.08149377Z",
"frequency": 867.5,
"modulation": "LORA",
"data_rate": "SF7BW125",
"coding_rate": "4/5",
"gateways": [
{
"gtw_id": "arjanvanb-gw-1",
"timestamp": 3548004372,
"time": "2020-05-26T05:42:41Z",
"channel": 0,
"rssi": -54,
"snr": 7.5,
"rf_chain": 0
}
]
},
"downlink_url": "https://integrations.thethingsnetwork.org/ttn-eu/api/v2/down/arjanvanb-app-ttnode/arjanvanb-http-ttnnode?key=ttn-account-v2.kFd<redacted>Vi_il4"
}