When I'm looking for the xpath for specific items on IOS-XE, I prefer to go and look for them using yangsuite. Different versions/devices implement different versions of yang models. You can check here the yangs models https://github.com/YangModels/yang/tree/main/vendor/cisco/xe
Yanguiste can be used as a docker container or pip package that you install locally. Then you add the device you are testing and the yangsuite can download the yang models the device is implementing.
From there, you can go to the protocol you want to use, in this case restconf and search for the model you are interested on. From that, you can navigate what the model expose and play around to get the data you want to get. In the yangsuite you can execute APIs directly, so the test is quickly.
See https://github.com/CiscoDevNet/yangsuite and https://developer.cisco.com/yangsuite/ to get more familiar.
IOS-XE, NX-OS, IOS-XR are supported by yangsuite. and other protocols as such as netconf and grpc.
You can download the yang models your device implements, but is much easier to go with the yangsuite.
EDIT: typos.
