No elevated privileges are needed
UIPI is a security measure that "prevents processes with a lower "integrity level" (IL) from sending messages to higher IL processes". If your program does not have elevated privileges, you won't be able to use enigo is some situations. It won't be possible to use it with the task manager for example. Run your program as an admin, if you need to use enigo with processes with a higher "integrity level".
You need to grant the application to access your Mac. You can find official instructions here.