Yes—being beyond arm's reach does not stop voice control. First turn the panel on, then use one of its listed commands while you are within about 2 meters (6.6 feet) and no obstacle blocks the path. If you are farther away or something is between you and the panel, move closer or clear the obstruction rather than assuming it can hear you.
When out of reach still works

“Out of reach” can mean you cannot comfortably touch the control panel, not that you are outside its voice range. The voice feature does not need Wi-Fi, but the panel must already be on before it can accept a command.
The BestQool Sauna Light is suitable when you want hands-free control while the panel is hung from a door or becomes warm during a long sauna session. Keep yourself within about 2 meters, with no door, wall, or other obstacle between you and the panel.
If an out-of-reach installation is part of your buying decision, compare voice control with touch controls for red light therapy to see which option better fits your session setup.
Clear space also makes the setup easier to use safely. Although written for workplace settings, OSHA's guidance to keep aisles and passageways free of obstructions is a useful general reminder when routing a panel cable near a sauna entrance or bench.
The accepted commands are listed on the back of the device. Read or photograph that list before placing the controls out of reach, because an improvised phrase may not be recognized. If a listed command still fails under the correct range and conditions, follow the full guide to fix unresponsive red light therapy voice commands.