The requirements depends mostly from count of Game Server instances and online count. As far as the online count of players increases it may be necessary to upgrade your hosting configuration.
Minimum requirements should not be lower than listed below - based on default Server configuration (1 Data Server, 1 Connect Server, 3-5 game Servers) with 90% players load
Hardware Requirements
• Processor
Minimum: 4x3.5 GHz, Recommended: 6x3.5 GHz or better
• Memory
Minimum: 12GB, Recommended: 16GB or more
• Disk Space
Minimum: 100GB, Recommended: 200GB - excluding Operating System requirements
Additional Software Requirements
• Operating System - supported platform x64 only
Windows Server 2012 or later, Windows 7, Windows 8, Windows 10 or later
• Database Engine - for MD5 Support select x86 SQL distribution
Microsoft SQL Server 2012 or later
• Visual C++ Redistributable Packages
Microsoft Visual C++ 2010 SP1 Redistributable Package (x64) Download - install on server machine
• Microsoft .NET Framework - to be installed on server machine
Microsoft Framework 4.8 Download
• File Compression - for extracting software shipped
Any which can support .rar extension, recommended: WinRAR or 7zip
• Configuration files editor - for easier viewing and editing
Any suitable for own needs, recommended: Notepad++
• Lua Scripting - for easy script edit and syntax check
The only and recommended editor is Lua Edit