Typing in a Keyboard shortcut

Hello, I've been having difficulty editing my keyboard shortcuts. Long story short Adobe Animate won't let me just type in the new ones I need (Ctrl++) for the zooming option and I can't copy and paste it in either. My drawing tablet is almost unbearable to use if I can't fix and change this one thing as I'm new to the program. I'm sorry if the question is silly but if anyone could explain how to fix this it would be much appreciated.