Transmission is slipping in reverse

The first thing we should check the fluid level and if okay lets service the transmission. this guide will help us get started. Do you have a check engine light on? If so these guides will help us:

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

and

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down these guides and report back.