iPhones don’t allow call recording without notifying the other person due to privacy laws. You can use third-party apps or external devices, but make sure to follow local laws.
I’ve been using Active Calls cloud-based call center software for some of my client interactions on my iPhone, and it automatically records calls without sending a notification to the other person. The saved recordings are easy to access from the dashboard, and it works well for keeping track of call details. It’s been a reliable option so far without needing extra steps or hardware.