Possible? Yes - very easily actually; especially for your use case.
You just need to create a discord bot that saves messages sent to a certain channel into a database. When the player opens that screen, request all of the stored messages in the channel (from your discord bot)
Allowed? This is very iffy. My first reaction is no - it could violate Roblox or Discord ToS. However, as I wrote the instructions on how to implement this, I suppose that perhaps it wouldn’t be different from just uploading text directly to the database with no Discord involved, which is allowed.
You will have to check with Discord’s ToS and rules about bots. I’m not sure what their policy about sharing messages outside of discord is via bot, but as long as they’re your own messages I would think that it’s ok.
I am not an expert in Roblox’s or Discord’s TOS and rules regarding this, so definitely check it out for yourself, but yes, this idea is possible.
This is very possible, just set up a discord bot that runs and fetches messages from a channel, since webhooks are only post and not get.
Once you have the bot up, set up a website or use a site like pastebin, upload all messages up to it, and you’ll use roblox’s HttpService to get the link and the data. I’d get the text when the server starts up, run it through FilterStringAsync, and then you can display it to all players.
I know running it through the filterstring function might seem useless, since only trusted people will access it, however glitches and errors can always happen, and it’s better to be safe than to have a swear word in your known issues list and getting your game deleted.
In regards to TOS, discord would be fine with it. The issue they have is that a lot of users were using webhooks as logging services, and sometimes hit rate limits and didn’t have any way to tell so they just continued sending requests to discord.
Roblox allows this as long as you run the text through filterstringasync, if you don’t, it would be breaking tos since it is making a http request for text that will be shown to a normal user.