With an SBB GA Travelcard (General Abonnement), what additional ticket do I need to ride the Aletsch Enduro Trails in the Aletsch Arena?

Enduro
It’s handy to have a GA Travelcard when you’re out and about in the Aletsch Arena, as it covers the valley feeder services (Mörel–Riederalp, Bettmeralp valley station–Bettmeralp, Fiesch–Fiescheralp). For the cable cars to the top (Moosfluh and Bettmerhorn gondola lifts and Wurzenbord chairlift), you can get the Aletsch Bike Pass, which is cheaper for GA Travelcard holders.