Fuel gauge not working properly

Hello,

The incorrect fuel level is likely due to a faulty fuel level sending unit.
The fuel level sender is located in the fuel tank, and it is a part of the fuel pump module. It consists of a float and a resistor panel. Over time the resistor can go bad and cause the gauge to read incorrectly.

In order to replace the sending unit, you will have to remove the fuel tank to get the fuel pump out.

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

I have attached diagrams below for your reference.

Please let me know of any questions.
Thank you.