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 Demo Portal account, sign up.
Use your Demo Portal account to create a P12 Certificate for JSON Web Token Authentication.
Demo Partner's Response code page provides
Demo Partner's Flex Microform solution provides tools to build PCI-compliant sites and apps. To understand all of the options available to you, see our Flex microform documentation.
You are responsible for maintaining communication with Demo Partner servers. Set your client applications that communicate with Demo Partner to direct requests to a host name and not an IP address.