Custom Creative Tab Backgrounds (Neoforge 1.21.1) (MCr 2025.2)

Hi, I was wondering if any one knows how to do a custom background on creative tabs. And if anyone knows how to add vanilla blocks to  custom creative tab that would be nice. Thanks in advance!

Versions:

• Loader: Neoforge
• Game Version: 1.21.1
• MCreator: 2025.2