To find out whether your library subscribes to Credo Online Reference Service or Literati, visit our "Where are you from?" page, which will present you with nearby libraries and allow you to search by library name or location. If you don't see your library there, you can always submit a support request to find out for sure.
To find out which platform you have access to, compare your account to the platform screenshots on this page, or submit a support request. (If you're not sure, the answer is probably Credo Online Reference Service, our basic platform). If you are the account's Admin, this information can also be found on your license.