I'm trying to automate a mining device but can't find error

Ok so here is the code
redstone.getInput("top")
if true then do
redstone.Output("left" , true)
sleep (1)
redstone.Output("front" , true)
sleep (2)
redstone.Output("front" , false)
sleep (3)
redstone.Output("front" , true)
sleep (1)
redstone.Output("front" , false)
end end

and the error is this
lua :3: attempt to call nil

is there something I'm missing if so please tell me

You're looking for redstone.setOutput, not redstone.Output. Also, you're confused as to how conditionals work. "if true then" will ALWAYS run the code inside it. This may be more what you were trying to do:

if redstone.getInput("top") then
    redstone.setOutput("left" , true)
    sleep(1)
    redstone.setOutput("front" , true)
    sleep(2)
    redstone.setOutput("front" , false)
    sleep(3)
    redstone.setOutput("front" , true)
    sleep(1)
    redstone.setOutput("front" , false)
end