Struggling with lack of undo button and it's deleted all my notes - what can I do to resolve this?

Hi everyone. I'm using the Integrity app and found it good so far but one of the most annoying things which is driving me insane and causing lack of trust as user is the fact when i use "ctrl + c" for copy it changes the text and then doesn't necessarily copy the text and then i have to go back to the UI page and then try again and sometimes it accidently deletes it and then what happens is basically I can't get it back and there's no undo button. How do I get my notes back? I