Yes for most of it, with one honest caveat. A lot of HYROX training is running, wall balls, burpee broad jumps, lunges and carries, all of which your trainer can coach and scale at home with a ball, a sandbag, or dumbbells. The sled and ski erg are harder to replicate, so closer to race day your coach will point you to a gym session or two for those and program everything else around what you have. You get a real plan either way, not something you have to piece together alone.