I’m pretty sure Roblox doesn’t like automated logins, that’s why captchas exist(to stop bots, that try to login or create an account automatically). However the behaviour you’re looking for might be possible through the Open Cloud API System. That’s Roblox’s recommended way of accessing it’s resources automatically(if I’m not mistaken).
I assume you need to host it somewhere. Although I haven’t messed with it so I’m not entirely sure if they provide some sort of hosting themselves. By hosting I mean have a machine running the code, that is often a machine dedicated to that aka a server.
Last time I checked you could get some sort of free hosting through using Github actions. Although that does not support 24/7 uptime but rather running the code on a fixed schedule/interval. If you’re interested in that a simple “github actions free hosting” query on Google should find you the related information.