Wix Forum - using HTTP POST for new post

I am trying to automate creating a new post using the Wix Forum by calling it with HTTP Post. I found the doc: Post Object | REST API Reference | Wix.com that covers what the object to post but i am still getting error 404 not found when calling out to the API. I am using:

Method: POST
URI: https://www.wixapis.com/forum/v1/posts/[ID]
Content-Type: application/json
wix-account-id: [ID]
Body: { sample from doc }

Where can i confirm the ID i am calling out to is correct? i know where to find the categoryId but havent found where the “id” can be found.
Has anyone been able to do this?

Thank you in advanced :smile: