Group Volume

I seen mention of setting the volume of the group when you use the say command. For example if I have a group of my sonos say welcome home or good bye or whatever and I want to set a global volume for all units involved using lua. Is that possible? Thank you…

Set parameter “Volume” to the wished volume level (from 0 to 100) and parameter “SameVolumeForAll” to value 1 (or true).