you need to create a float variable. so in the left you set that variable storing a value on it. Then on the right, the tick uses the new stored value to rotate the object.
also, in the left, make sure to set the timer to looping, otherwise it will happens only once. The Time there (5) means that every 5 seconds the system will update the float variable value to a new random value. And in the random float in range, set the values you want to generate there. Too high values will rotate too much, I used -3 to 3 as reference to test