Trying to find find or design 2x20 GPIO header in altium
I ALWAYS recommend creating your own libraries when working within Altium. Using third-party or built-in libraries leads to mismatch in styles that can be confusing to you or to your viewers. It also allows you to create custom parts that may not already exist in libraries, as I expect may be your case. I created a tutorial on how to make your own libraries in Altium Designer. You can find the video here: https://www.youtube.com/watch?v=-kyY25CGJtM

The video walks you through how to start your own library and how to use the manufacturer's datasheet/part drawings to generate your own symbols and footprints.