I am unable to parse a JSON?

I am trying to retrieve a JSON table and it is unable to convert it back to a lua table: returns: >["Index":0,"Id":100,"Count":1]<

Database (serverside):

...
local SaveId = tostring(MD5.sumhexa(tostring(Player.UserId)))
local Inventory = Inventory_Data:GetAsync(SaveId) or "[]"
print(Inventory)
Return = HttpService:JSONDecode(Inventory)
...

Just a simple one I hope. Thanks.