You can try calling and see if a staff member will do it for you. It is against the rules in most places, but sometimes if you're nice they will make an exception. The alternative is to write them a letter or postcard to let them know what's up.
https://www.inmateaid.com/ask-the-inmate/can-i-call-the-jail-where-my-friend-is-and-ask-them-to-put-my-number-on-his-call-list-or-do-i-have-to-just-write-him-and-wait-till-he-gets-the-letter#answer
Accepted Answer Date Created: April 12,2019