Retrieves a site's word credit data.
For sites with a limited quota, you can calculate the available word credits by subtracting the credits used from the quota.
For example, if a site has a quota of 100 credits and all credits have been used ("creditsUsed": 100), the available word credits will be 0.
If a Wix user purchases an additional 50 credits, the quota will increase to 150, and the site will have 50 available word credits.
You can only call this method when authenticated as a Wix app or Wix user identity.
This method doesn't return any custom errors, but may return standard errors. Learn more about standard Wix errors.