Go to the Devices tab and verify that your device has an associated Thing. If not, you must either create and new Thing or associate an existing Thing with the device.

Go to the Things tab and open the Thing that’s associated with your device. Then go to the Devices tab, and find your device in the list. Under Network, click on Change and verify that your credentials are correct.

• Wi-Fi: Make sure the name (also called SSID) and password (also called encryption key or just key) are correct. The password can be revealed by clicking the eye symbol. If you don’t know your network name or password, contact your network administrator or the manufacturer of your Wi-Fi access point. If your device has a secret key, make sure it’s entered correctly (if you’re unsure, remove and re-add the device to generate a new key).
• Arduino SIM: Use these credentials. Make sure a working GSM antenna is connected to the board and that an Arduino SIM plan is activated with your account.

Open the Thing’s Sketch tab. Make sure the right device is selected and re-upload the sketch.

Fully delete the device, then add it again as a new device. For detailed instructions, see Add and connect a device to Arduino Cloud.

Test your setup with an example from the ArduinoIoTCloud library. Upload using Arduino IDE or the Cloud Editor.

Check your device’s power supply. Avoid using a USB hub, and instead connect the board directly to a USB port or another power source with a reliable cable to ensure sufficient power.