Won't go into reverse

If the fluid is low then that will cause this as it is not able to build the line pressure needed for reverse. So we need to start with this and here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-and-add-transmission-fluid

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Once the fluid is the correct level and if the vehicle still does not move in reverse then we need to check the line pressure to find out what is happening inside the transmission.

Please see the attached documents that will help with completing this.

Please let us know what you find and we can go from there. Thanks