How do I award player points to a player for every 10 minutes they play?

I have created a script that awards 1 player point every 10 minutes when the player is playing the game. There are a few problems:

1) When I tried to test this script, I put in a print(pointsToAward) so I could see them, but this returned an error. 2) This only fires once. I wanted to put in a while loop but I didn't know what the best way to do it would be.

Can anyone help?

game.Players.PlayerAdded:connect(function(player)
    local pointsToAward = PointsService:GetAwardablePoints()
    wait(600)
    if (pointsToAward > 0) then
        PointsService:AwardPoints(player.userId, 1)
    end
end)