Webhook URL issues

I am trying to create a webhook trigger that works with a third party service

I have created the automation with suitable webhook id. I have then obtained the public URL exposed by Nabu Casa. I have tested this URL with a curl command and it’s working fine

However the integration with the third party service is not working and I believe it is because that service is appending additional fields to the URL I give it

So I and giving the service the URL: https://hooks.nabu.casa/“some URL content”

It is then POSTing to: https://hooks.nabu.casa/“some URL content”/“fieldA”/“fieldB”/“fieldC”

I have tried posting to this modified URL using a curl command and as expected I get a “not found” error response from nabu casa (I assume)

I have no control over the third party service appending these fields

Is there any way to create a webhook trigger that will accept additional fields?