How do I really use a Region3.new?

Hey there, I want to make a Region3 and then it prints the name of all the parts inside of the Region3 however, I have no idea how I could make it to where it prints all the parts inside of the Region3 I know how to make one...

local player = game.Players.LocalPlayer
local char = player.Character
local mouse = player:GetMouse()


function getParts(origin, radius)
if key == 'q' then
local a = origin - Vector3.new(radius, radius, radius)
local b = origin + Vector3.new(radius, radius, radius)
local region = Region3.new(a,b)
local parts = region:findPartsOnRegion3(
region,
char,
100)
end
end

function activateSkill(radius)
--This is what I don't know what to do in order to print all the parts name in that region.
end

mouse.KeyDown:connect(getParts)

Thank you for reading my question all the way and I hope at least one of you can help me out with this issue I have.