How i can test lead API key, weather its working or not?

How i can test lead API key, weather its working or not?
Path : https://account.solidperformers.com/settings/lead_capture_apis

1.API settings
2.Lead Capture API.
3.View that respective API details
4.Copy the Sample Curl code.

Reference image.

To test this you have to create an POSTMAN account by referring the mention URL https://www.postman.com/
After creating an account, login to your account.
1. click on import.
2.click on Raw text
3. Paste your code which you have copied from CRM.
4.Click continue.
5.import.
6.click on body.
7.enter your data, like email and phone.
8.And click on send, if it sent success message then it will be working. and you can also cross verify the leads capture by checking lead module, And still you are not able to receive leads, then check the integration from end.

Reference images.