Are you talking about a case rolling system? If so, this is quite simple and has so many open sourced versions.
Or, are you talking about something like CSGO? Where the skin itself is literally random and super limited, like a random pattern but a same skin colorway, this would be super hard to replicate on Roblox.
First of all, you can’t request scripts or stuff like that.
Second of all, can’t you just make a script to change the texture of a model when a certain button is pressed? Shouldn’t be too hard to code.