I think there is some confusion of IP addresses and URLs here. Therefore, I have pasted images of my Hubitat (Maker API) and Node-RED Hubitat config node setup with explanations below:
Here is the Maker API setup on Hubitat:
Here is the Hubitat config node setup on Node-RED:
Make sure you enter the access token (from Maker API) correctly over here:
You do NOT need to have the node-red-contrib-webhookrelay palette installed on your Raspberry Pi.