The speedometer is broken.
The speedometer gets the vehicle’s speed from the transmission. There are two speed sensors used to control shifting. Input speed and output speed. The output speed sensor is used for the speedometer. If it malfunctions, it will store a trouble code. This is the most common problem for the speedometer not working. But it could be the gauge itself, or the wiring involved. I’m not positive about your specific car, but most cars when you turn the ignition on, all the gauges will do a “sweep”. This informs you that the gauge is working. If you would like to have this repaired, have a certified mechanic diagnose your speedometer issue to determine what should be fixed.