Creates a tier.
The name for a tier and the amount of required points to qualify for a tier can only exist for a single tier.
Attempts to create a tier with a tierDefinition.name or requiredPoints that already exist return an error.
To create up to 20 tiers at once, call Bulk Create Tiers.
Note: A site must have a Plus plan (Wix Studio) or a Business plan (Wix Editor) to add tiers.
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.