Shifter stuck in reverse

More than likely this is a shift cable issue so I would suggest we start with this.

Does the vehicle start and run when it says it is in reverse or does it not start either?

https://www.2carpros.com/articles/ignition-switch-wont-turn-stuck

If the key won't turn either then we could have a different issue but let's clarify this and go from there.

Below you will find the testing from the manual on this but I also included the process on how to replace and adjust the shift cable as I suspect this is the issue.

I would suggest removing the cable from the transmission manual valve lever and then try and move the shifter. If it moves then we need to move it to park and put the transmission in park and then adjust the cable as shown below.

Please let us know if you have questions or what you find.

Thanks