Delhi doorstep delivery of certificate not available

I'm Naman residence of delhi who wants to make income certificate for my father to submit in school but SDM office doesn't issue it with an ease they are very irritating and lazy staff and always deny for service but when I came to know about Delhi doorstep delivery of certificate then I have been trying to apply for this but OTP on website not coming on my mobile number and call on 1076 is not picked up since many times