Integrate Razorpay quick payments plugin with contact form7 plugin

You need to integrate a a custom field tag into your form so that the cf7 validation process correctly identifies your required field. To do this you need to create a custom field tag using contact form 7 hook functionality, the details of which you can find on the contact form 7 official website. Googling how to add custom form tags in cf7 also points to similar answers in this forum.