I usually use call recorders during work. I found nice app here https://apps.apple.com/us/app/call-recorder-icall/id1447098963 and its work simple for recording incoming calls from partners. Record phone calls in one tap for later use with iCall.
I will glad to help you. Because I use PDF scanner for different options for scanning and save documents and books for studying. I found good pdf scanner for Iphone which works well. Try to use it too, when you have Iphone.