Not in its documentation, but atop requires root. If you're on a VM somewhere, you might be happier with htop or glances.
I'm not sure what being on a VM has to do with anything.
It would be nice if there was a way (e.g. a command-line argument or atoprc setting) to disable the ability to kill processes from within atop; then it would be safer for an admin to make it executable as root by regular users.
For interactive use it is sufficient to install ATOP with the command (as root):
make install
I wouldn't have guessed the reference to root was optional! Thanks for the pointer.