Execute adds all child commands to the root command and sets flags appropriately.

ApplicationId is the app that the key is issued for.

Brand name to say who the message is from.

Code supplied by the user.

From sets who the sender should be (restrictions vary by geography/carrier).

Key is the user's API key.

Message to send.

Number is the phone number to confirm ownership of or access to, in E.164 format.

PrivateKeyFile is a path to the private key **TODO** What about env var support?.

RequestId identifies the verify request once it has been created.

Secret is the user's API secret.

To sets who to send the message to.

TTL is the validity period of the generated token, in minutes.