Unable to reach Insightvm API end point

I have generated my API key, Iam able to fetch data from Insight IDR using postman and CLI, when trying the same with VM API endpoint Iam not getting response.
VM end point that I tried: https://help.rapid7.com/api/3/assets.
gave my api key in header in postman as well as CLI.
can some one let me know what Iam doing wrong.

Are you using the right URL when calling the API? It should be based on your InsightVM instance, not just help.rapid7.com

Ok will check that