i started to use the Marketing Cloud recently but i'm facing some problems to update a Preference Attribute using the FuelSDK (ruby). So, basically i can just update the profile attribute seding the content through the API (sending the desired field on the Attributes tag during the SOAP request), but i can't do the same strategy to update a Preference Attribute.
Currently, i'm interesting to set some values (Profile and Preferences attributes) when i create a subscriber triggering a first email for the user (when the user create a new account) through the Triggered Email action.
I don't really know how i can update a Preference Attribute using the FuelSdk.
If someone could give some tips, i would appreciate it.