Ok, how do I adjust for altitude in Biabacus. Specifically relative to hops utilization during boil.

I hate brewing beer in a bag but only because it has quickly become my crack....... 3 all grain batches since Feb, 2 split batches under my belt. First batch was on a buddy's equipment. The following were BIAB I use a Keggle and associated keggle lift rig (doubles as a lawn tractor lift) lift rig.pn...