Be very very careful about what Adob Plan you pay for
Lightroom Plan, just that IMO LOUSY Lightroom a.k.a Lightroom Desktop a.k.a Lightroom Cloudy. Runs on computer, saves Albums on the Coud, saves photos on the Cloud. Highly less feature rich than Lightroom Classic.
Technically you can install them on as many machines as you desire but only TWO activations per license. But you could install on say three machines, have two activated. Deactivate on one, activate on the third. Go back again. You can mix and match OS.