Yes, it is right there. Drag the bar across the graph and look at the altitude reading on the right hand side. At about 5:10 PM PST it ascends from 37k to 39k ft. and at it doesn’t begin to descend again until about 6:20 PM.
Sigh. Did you scroll down a bit on that page and review the minute by minute breakdown of locations and altitudes of the aircraft. It ascends from FL370 to FL390 between 3:55 and 4:05PST and starts its descent from FL390 at 5:27PST.
You are a case study in the type of person who bites off on conspiracy theories and why.