Where are you trying to create this control? Are you still planning to handle the motion in the PLC using the KinInterface?
The internal variables used by the KinInterface library, and referenced in the faceplate from your image, are not written automatically to the datalayer.
If you would like to interface with the CXA_MotionInterface functions in your PLC via an external method (OPC UA), you will need control variables exposed in your symbol configuration file (ie. enable, jog, home etc.) that then call the corresponding KinInterface function in the PLC. You could also expose the status of your KinInterface functions in the same way.
If you are just looking for control and status, and don't necessarily need to use the KinInterface in the PLC, I'd suggest controlling the motion application via the datalayer directly.
See the node descriptions here: ctrlX Datalayer Motion Nodes
See the Node-RED control examples here: node-red-contrib-ctrlx-automation
