I was wondering how can I pick a square object with no distinct features on it with the vision system?

Squares are pretty distinctive themselves. It should work unless there are similar squares in your background

To add to @Vincent_Paquin's answer. You can use the camera locate node with the Robotiq wrist camera and there are no special tricks to it, this is standard programming for this product. If there are no special features to identify on the object then it may be hard to predict how the object will be picked up by the robot. It will always be picked at the same place on two edges but it is hard to identify the edges that it will be picked from. Figuring out which edges it will pick first will depend on matching results. This matching result can depend on many different environment variables such as lighting that may change while the program is running. Anyhow, no matter from which edges the part is picked the robot will always drop this in the same orientation afterwards since the object is square. See the following video with a demo that I made for you using a 3’’x3’’ post-it with the program!

https://youtu.be/SkhT_A0KrCM

 Program

   Robot Program
     MoveL
       Waypoint_1
     Camera Locate
       MoveL
         Waypoint_2
         Gripper Move 54%
         Waypoint_3
     MoveL
       Waypoint_4
       Waypoint_5
       Gripper Open

At the moment, there is nothing allowing to do that.