Hey i was trying to implement this
chance  = 98
nextbet = 0.00015
bethigh = true

local rollsData = {}
function dobet()
    local betIdString     = tostring(lastBet.Id)
    local betIdNonce     = tostring(lastBet.nonce)
    local betIdRoll     = tostring(lastBet.Roll)

    print(betIdNonce .. betIdString)
    local f = assert(io.open("quicksave.txt", "w"))
    io.output(f)
    f:write(betIdString, "\t")
    f:write(betIdNonce, "\t")
    f:write(betIdRoll, "\n")
    f:close()

end

Where i want to save few bet properties to an external text file.
but i can't perform append operation as i am getting this error.
[string "chunk"]:10: quicksave.txt: error #-1

Before addressing the append issue, why do you want to save it to a file?

Are you aware that all of your bets are stored in a sqlite database called dicebot.db? You can browse and query the database using a program like sqlitebrowser.

didn't knew that all bets are stored inside sql database dicebot.db.

Will check that out thank you