Thank you all, I also notice that full tank refueling reset the average fuel, I had 240 Allion previously and it can be changed by hold the display change button I thought there is a way to do in 260 also because 2018 260 model has the feature to reset.
In Prius 2014 model can be reset the average fuel consumption by set the mileage display to trip and then the average fuel can be reset by holding the change button, that's why I thought in 260 Premio/Allion may have hidden feature. By the way thank you all and if you got a please reply me.