Transmission does not change gear

While driving lost the speedometer. Stop to eat and when I started the car, no speedometer, and the transmission did not seems to change gear and while I did put more gaz the RPM went higher but again the transmission did not change gear, drove on first or second gear only. The transmission fluid is good color, no noise and no shaking while driving.
What can be the problem a sensor or need a new transmission or work on the transmission?

Thanks for the attention given to the present question.