I would recommend you use SimpleAdmin. It’s open source, updated weekly, and community driven. It’s also made to be flexible, featuring a custom class-based UI kit and a package system that’s really easy to use. If you’re really interested, you can look into using SimpleAdmin Pro. It lets you control your game from a Discord bot and lets you access your game from a custom API.
You can let me know if you have any questions about the system and I’ll help you out.