• Check that you have switched on cellular data in the phone's Settings.

• Check the SIM card is inserted correctly and that it's in contact with the metal connectors.

• Make sure you are connected to the appropriate cellular network – confirm that you are in an area that has coverage of that network.

• Restart the device if necessary.

• Check if the device is compatible with the network – if not, you can purchase an appropriate SIM card and switch networks.

• Contact the cellular provider to check their services, network status, and any potential cellular issues.