Team Kill Leaderstats

I want to make in the leaderstats to total the kill and death of a team, not only total kill and death each player , how can I do it?

You can just loop through all the players on a team and add all the values up to get the total:

local totalKills = 0
local totalDeaths = 0
for _, p in pairs(game.Teams.Team:GetPlayers()) do
     totalKills += p.leaderstats.Kills.Value
     totalDeaths += p.leaderstats.Deaths.Value
end

Have you set a Team object? If so, the total of a whole team on the leaderboard is added up automatically.