How to add customer in Zoho invoice**

Hello

Can u please provide me the way to add customer information in zoho invoice through API (And if i am adding customer information from a simple HTML form).

I just need to add customer info through submit form and it should also be added in Zoho invoice too through API.

Please provide me the PHP build /script to add customer or to make connection with Zoho DB to insert data .

Need to solve it ASAP.

Regards
Priyanka