You can sign up for a Sandbox Account here
After you sign up successfully, you should receive an email with instructions to create Sandbox Account on Enterprise Business Portal
If you do not receive an email,
If you do not have a Merchant Portal account, sign up.
Use your Merchant Portal account to create a P12 Certificate for JSON Web Token Authentication.
You are responsible for maintaining communication with Cybersource servers. Set your client applications that communicate with Cybersource to direct requests to a host name and not an IP address. For more information, see best practices for communicating with Cybersource.