Krita 4.2.9: How to add brushes on Krita.

You can add new brushes on the Krita application using the Main menu - Settings - Manage Resources...

One good option is to use free brushes from KDE website, see this web page.

This will open a new window and use Import Brundles to import the brushes into Krita.

Krita 4.2.9: Another new released Krita.

This new released of Krita 4.2.9 was made on March 26, 2020 comes with new fixed options and .
The full released note for versions 4.2.x can be found at this webpage.
All download versions: Windows Installer 64-bit (106MB)
Windows Installer 32-bit (105MB)
Windows Portable 64-bit (146MB)
Windows Portable 32-bit (145MB)
Mac OSX Installer (186MB)
Linux 64-bit Appimage (198MB)
You can used with these operating systems:
Operating System: Windows 8.1 or Higher, OSX 10.12, Linux
RAM: Recommended 4GB or higher
Optional GPU: OpenGL 3.0 or higher
Graphics Tablet Supported: Wacom, Huion, Yiyinova, Surface Pro
You can find many options to learn to use the Krita software.
The good one is the official youtube channel comes with news, see for example the RGBA brushes how works and is fixed: