How can I stop people from viewing my plugin's code?

I don't think you can. The best way to hide your code is to obfuscate it so people have a hard time reading it. There are some plugins on Roblox that can do that for free.

Obfuscation is generally terrible unless you're using a paid obfuscator reserved for usually exploiting scripts (unless you're going to modify LBI yourself, which is pretty hard). This generally wouldn't work anyway because it's always possible to deobfuscate it. If you don't want it to be public, then just don't let people get the plugin.

Yes. Robloxians can get the source plugins (even games).

I don't know how, but the best way possible is to obfuscate your plugin and make it cost robux.

MikePetar told me about this.

So you should probably obfuscate your script.