Express server went down and can't be pinged

I was running a Discord bot on Replit, and I tried to use keep_alive.js file, google apps script , and uptime robot to let the bot online for 24/7. However, the bot still went down after a few hours.
When I opened the file and looked at the web section, there were no texts. I have no idea what cause this.
There is my file: index.js

Hi @Tobydog0501 thanks for your message!
Have you got “Always on” selected for the repl?

I don’t have hacker plan so I can’t select “Always on”

Hi @Tobydog0501 then as far as I know you won’t be able to always have your Repl running.

I see, thank you for answering my question.

UptimeRobot dropped support for new *.repl.co links since April 1. If when this happens you have a ready event which is meant to display a message when the bot is online, but the message doesn’t display, you may have been ratelimited. Rate limits are caused by too many requests, especially invalid ones, from the same IP that is shared across multiple repls.

require("replit-dis-uniter")(client)

before client.login() sets everything up to get your repl alive for most of the time. Not 24/7 because the repl restarts occasionally to switch container, and the package makes it restart when there’s a rate limit so it can switch to a potentially non-ratelimited IP.