code: def validate_payment_form(self):
          
          warn_untested()
          form = self.payment_form_cls(self.request.POST)
          if form.is_valid():
              success = form.process(self.request, self.item)
              if success:
                  return HttpResponseRedirect(self.success_url)
              else:
                  self.context['errors'] = self.errors['processing']
  
          self.context[self.form_context_name] = form
          self.context.setdefault("errors", self.errors['form'])
          return TemplateResponse(self.request, self.payment_template, self.context)
docs: Try to validate and then process the DirectPayment form.