So, I am trying to create a discord bot that acts similar to the not quite nitro bot. Launching the bot has no problems, but the problem arises from when I attempt to use the bot.

after using the bot for its function, it throws this error in the terminal:

ReferenceError: StartDelimiter is not defined

at get_substrings_between (C:\Users\\Nitrolite\index.js:65:32)
at Client.<anonymous> (C:\Users\\Nitrolite\index.js:12:26)
at Client.emit (node:events:527:28)
at MessageCreateAction.handle (C:\Users\\Nitrolite\node_modules\discord.js\src\client\actions\MessageCreate.js:26:14)
at Object.module.exports [as MESSAGE_CREATE] (C:\Users\\Nitrolite\node_modules\discord.js\src\client\websocket\handlers\MESSAGE_CREATE.js:4:32)   
at WebSocketManager.handlePacket (C:\Users\\Nitrolite\node_modules\discord.js\src\client\websocket\WebSocketManager.js:351:31)
at WebSocketShard.onPacket (C:\Users\\Nitrolite\node_modules\discord.js\src\client\websocket\WebSocketShard.js:444:22)
at WebSocketShard.onMessage (C:\Users\\Nitrolite\node_modules\discord.js\src\client\websocket\WebSocketShard.js:301:10)
at WebSocket.onMessage (C:\Users\\Nitrolite\node_modules\ws\lib\event-target.js:199:18)
at WebSocket.emit (node:events:527:28)

as for the lines of code themselves:

    var StartDelimiterLength = StartDelimiter.length;
function get_substrings_between(str, startDelimiter, endDelimiter) {
    let substringArray = get_substrings_between(message.content, ":", ":");