What state is he in? The Department of Corrections should have a link to add money, but only if he has an inmate number assigned to him.
https://www.inmateaid.com/ask-the-inmate/my-brother-is-in-county-jail-and-will-probably-be-transferred-in-a-few-days-to-prison-facility-how-can-i-make-sure-he-has-funds-available-for-things-he-will-need-when-he-arrives-at-the-prison#answer
Accepted Answer Date Created: September 26,2016