An apology for insisting so much but nobody has solved my doubt yet.
It happens that I want my active directory users to authenticate to the captive portal according to what I have seen and researched should be added the server and the domain in the “Realms” part of kerberos 5 and in the authentication of the portal add the domain In external kerberos 5 realms and with that should be enough but my users do not authenticate in the portal with their credentials of active directory if someone could help me I would be very grateful