Questions to integrate paypal with zoho.

Questions to integrate paypal with zoho.

1. Do I need to setup the paypal developer before I could integrate with zoho?      
2. I followed the instructions in  https://www.zoho.com/creator/help/forms/accept-payments-through-forms.html#Creating_a_Payment_Form How can I configure the submit button so that it will linked to paypal website to make payment?
3. Can anyone please provide a step to step guide so that i could follow? 

THANK YOU!!!