How to fetch data from estimations in zoho invoices?

How to fetch data from estimations in zoho invoices?

Hi, I am working with zoho invoices and want to fetch data of estimations from Zoho invoices using Zoho api using php curl, now i have tried 3 to 4 different solutions but none works, please don't refer me the official site's documentation i have read it 4 times and i'm not able to do what i want. To sum up i need the php curl url to fetch data from estimation module in zoho invoices.Thank you.