You need to keep looking. 
There are two different ways to handle this.
A) look for “stackable“ smart plugs which don’t cover the other receptacle in a wall outlet. See the following discussion thread:
B) choose a pocket socket with two outlets where each is independently controllable. There aren’t many of these, but there are a few.
https://www.thesmartesthouse.com/collections/zooz/products/zooz-z-wave-plus-s2-double-plug-zen25-with-usb-port
