request
Request server to send PUK code to the user.
If there is no default wristband then GoBeNotSetException will be emitted.
If wristband state isn't connected then ConnectionNotStarted will be emitted.
If some error occurs during wristband interchange then GoBeCommandException will be emitted.
NOTE: User must be valid and wristband must be connected.
Return
Completable that completes when request finished