Renames an extended field.
You can only call this method when authenticated as a Wix app or Wix user identity.
Extended field key.
When accessing contact data,
extended field data is available at extendedFields[key].
For example, if the key is "custom.notes",
the value can be accessed at extendedFields["custom.notes"].
key is generated when the extended field is created
and can't be modified, even if displayName changes.
Extended field to rename.
Renamed extended field.
This method doesn’t return any custom errors, but may return standard errors. Learn more about standard Wix errors.