How to add Attachment Custom Field on payments

Hello can anyone help me with add an attachment field on the payments section ,on creation of new payment

Attachments and custom fields are two completely different things. There are Guides about both.

When you created the payment, you can attach files when viewing the payment (left below the view screen).

ohh sure i wanted to be able to add attachments on my payments

So did you reach the Guide about attachments?

yes i did thanks alot