can't change application's icon
Hi, Im using mac OS mojave. I've tried to change Kiwi's icon (email app). I dragged file *.icns to the top-left corner of the app's info and the icon changed. But the problem is that when I start the app the icon changes to the original one. How to fix that? The way I described above worked for Catalina previously but something's wrong on Mojave. Any ideas? Thanks in advance .
MacBook Pro 13”, macOS 10.14