21708: Alpha Sender ID Missing from the requestWARNING: 21708warning-21708 page anchorPROGRAMMABLE SMSWARNING Descriptiondescription page anchor Error - 21708error---21708 page anchor Alpha Sender ID Missing from the requestalpha-sender-id-missing-from-the-request page anchor Possible Causespossible-causes page anchor Ensure that a request contains an alphasender in it Possible Solutionspossible-solutions page anchorPlease include an alphasender in the request