To make a test Payment in Sphere use the following information:

Billing address fields: [can be anything]
Cardholder name: [can be anything]
Card #:  4111111111111111
CVV:  123
Exp. Date:  [any date from present]

When testing a payment if you find that the payment fails to submit, check the following:
  1. That the card information is submitted properly.  Card # and CVV are exact.
  2. That the site providing the form is in Preview mode.  Test payments are only possible when an initiative is in Preview mode.
If you have moved the initiative to Active prematurely, you can Duplicate the initiative and set that new site in Preview.

If this does not resolve the issue or you have questions about any part, Chat with Support and reference this article.