Yes, and that step cannot be skipped regardless of which service you use.
The application process is controlled by the facility, not by InmateAid. Every jail and prison requires anyone who wants to receive calls from an inmate to be on that inmate's approved call list. Getting on that list means submitting an application through the facility's phone carrier, whether that is Securus, GTL, IC Solutions, or whoever holds the contract at that particular jail. That carrier will verify your information and approve or deny the application before any calls can go through.
InmateAid operates on top of that existing system. What InmateAid does is provide a number that reduces the per-call cost once you are already approved. But the approval itself happens through the facility's process first, and there is no way around it.
The practical sequence is this: complete the phone application with the facility's carrier and get approved, then set up your InmateAid number and have your inmate add it to their approved list. Once both steps are done, calls come through at the lower InmateAid rate.
If you are not sure which carrier the facility uses or how to start the application, InmateAid can point you in the right direction. The approval timeline varies by facility, so starting the application sooner rather than later means fewer missed calls while you wait for the process to clear.