How to enable MBstring option with my WHM/CPanel VPS Account

Login to WHM as root
Go to search box and search easy like and select EasyApatche4/5 etc

2. Click on Customize Button

3. After that select PHP Extension like following and search MBString

4. Enable all MBString Module and select next
5.Proceed with Build & Compile Process
6. Make sure you wait for the build to complete.