How to identify SSO ID for Digital Adoption Platform?

<script>
window.Appcues.identify(
  "<<< USER_ID >>>", // unique, required
  {

    // recommended (optional) properties

    createdAt: 1566932390, // Unix timestamp of user signup date
    purchasedAd: 1566932395, // Unix timestamp of account purchase date (leave null if empty)
    planTier: "Standard", // Current user’s plan tier
    role: "Admin", // Current user’s role or permissions
    accountId: "1234", // Current user's account ID
    firstName: "John", // current user's first name

    // additional suggestions

    companyName: "Acme Corp", // Current user’s company name
    email: "john.doe@example.com", // Current user's email
    location: "90210", // a zipcode, state, or country enables location-based targeting
    version: "2.0", // users on different versions may need to see different content
    language: "spanish", // for multi-language applications
    renewalDate: 1577880288 // to remind users to renew
  }
);
</script>

I'm looking to add a Digital Engagement Platform via JavaScript on to my community. In order to track users we need to provide a unique identifier for each user. 

I've copied the sample script from their website and they identify what is supposed to be swapped out.

However I'm having trouble identifying what should be used for the SSO ID value in the sample code above in place of "<<< USER_ID >>>"

After the correct syntax is determined I also need to ensure it is being placed in the right place  in Stuido > Community Style > Wrapper > Custom Skin.

Any other information on how I can identify other fields would be helpful as well.

For example we might like to do the following.

• Trigger at number of visits
• Trigger # of days after account creation date
• Trigger at specific Rank
• Trigger with specific Roles
• Trigger for sponsor status
• Trigger for certain companies
• Trigger if custom date is Today
• Trigger for certain languages

From Page Hitbox I'm seeing:

standard fields: 
<#assign khorosUserID = user.id />
<#assign communityUsername = user.login />
<#assign emailAddress = user.email />


We also have some custom fields 

<#assign quitDate = user.get("profile.quitDate")!"No quit date selected" />
<#assign payerInfo = user.get("profile.company.name")!"" />
<#assign eligibleForNRT = user.get("profile.nrt")!"false" />
<#assign personID = restadmin("/users/id/${user.id}/sso_id").value!"" />
<#assign sponsoredStatus = user.get("profile.sponsored.status")!"" />
<#assign language = user.get("profile.language")!"" />

I do also see in the hitbox

personID = '${personID}';

Hopefully someone can point me in the right direction so I can learn this a little better and expand upon it.

TIA