Adding form input in deferred payment method

Is this possible to add input fields in the payment form especially in deferred payment method? I want to collect some info in this payment method.

No, you can only add fields to the products and the order. The payment forms are generated server side.
The order custom fields will be for the whole order (like adding customer informations). In the documentation there is an example of adding a phone number to the address fields : Customization – Snipcart Documentation