Using android studio and mongo DB realm - How to push an update to an array in my object

I have been trying to push an update to an array in an object within our database. It is being connected with realm and I am using java in Android Studio, I can successfully replace the whole object but when I try to do an update I am not able to just get a push to the array of that object. I have been trying to use the $push operator to not avail. Was wondering if there was another place I could see some syntax of something similar to another way to push since the example syntax for a lot of these aren’t applying to android studio.