The power switch is located at the top of the battery pack accessible behind the velcro closure on its back. If you are having problems personalizing My Pal Scout/Violet Smarty Paws, you may need to turn the power switch to OFF (far left), then ON again (right).
Note that the power switch is not reachable while My Pal Scout/Violet Smarty Paws is still in the packaging. You will need to remove it from its box to access the power switch.