You can send a postcard or letter to your loved one and include your assigned number. Or give them the number the next time they call. Also a lot of jails have implemented emails.

Well i gave it to them over the phone or you can send a letter with it on it to them

They don't. This site is a scam. Please dont give them any money or time. They do not work. Nothing about this site is legit.

Everyone in jail should have email access or some kind of contact. When I got the phone number from pigeonly, I emailed it to my loved one and they called to try it out. It was great!