I have a new laptop without a numpad. I now enter dimensions with the top row numbers using my left hand which avoids me releasing my mouse. I would like to assign an additional key for ‘enter’ on the left hand side somewhere so I don’t have to reach to the far right 
everytime I enter dimensions. I can’t find what the edit/enter command is in the shortcutlist.
Thanks. Know it’s a dumb question.
SketchUp is not a command base app, it is tool-operated, based on selected entities.
Therefore, it’s shortcuts can only handle those.
There are keymapping tools for altering keys in the OS:
Also the latest version of Microsoft Powertoys has a keyboard remapping app
I have an extended keyboard for my Mac. I wish you could get one with the number keypad on the left so that, like you, you can input numbers with the left hand. And if it had an enter key too, that would be just dandy.
Doesn’t solve it for a laptop of course…
Work it with your toes if you want.
These kinds of things are available for PCs, too.