How to verify UserHasBadge before TeleportService?

Well, you want to define the player, so what I do is find the player's name in PlayerService. But you also don't want a random object hitting the brick messing your script up.

BadgeId = 106566897 --Testing Badge


function onTouched(hit)
    character = hit.Parent
    if character then
if game.Players:FindFirstChild(character.Name) then --Need to see if it is a player or random object.
local player=game.Players:FindFirstChild(character.Name)
        if game:GetService("BadgeService"):UserHasBadge(player.userId, BadgeId) then
        print("The user has this badge")
        print("Teleporting user to next level")
        game:GetService("TeleportService"):Teleport(158451458, player)
    else
        print("The user does not have this badge")
        print("Teleport disabled")
        end
    end
end
end

The reason your's is not working is because it is not referencing a character in the script. Hit.Parent may be a model or a gun. To do this you must reference a character. As so:

local char = Hit.Parent:FindFirstChild("Humanoid")
local plyr = game.Players:GetPlayerFromCharacter(Hit.Parent)
if char ~= nil and plyr ~= nil then -- ~= nil means not equal to nil.
--Rest of script
end