**To attach a certificate to your thing** The following ``attach-thing-principal`` example attaches a certificate to the MyTemperatureSensor thing. The certificate is identified by an ARN. You can find the ARN for a certificate in the AWS IoT console. :: aws iot attach-thing-principal \ --thing-name MyTemperatureSensor \ --principal arn:aws:iot:us-west-2:123456789012:cert/2e1eb273792174ec2b9bf4e9b37e6c6c692345499506002a35159767055278e8 This command produces no output. For more information, see `How to Manage Things with the Registry <https://docs.aws.amazon.com/iot/latest/developerguide/thing-registry.html>`__ in the *AWS IoT Developers Guide*.