SketchUp for schools account question

I’m a longstanding SketchUp Pro user and I’m teaching a high school 3D modeling class at Community High School In Ann Arbor, MI this semester (purely voluntary I’m not being paid). I was under the impression that SketchUp Pro was free for k-12 students. Does anyone know how this works? My kids have been using free trail versions of SketchUp pro for the time being (as a placeholder while we figure out how to set up their accounts for the semester).