Excalidraw: Can not setup a custom icon library with self designed images. Why is it so difficult?

What I’m trying to do

What do I want to achieve:
→ a custom icon library accessible in excalidraw (without going to another program like explorer or directory)
→ a custom icon library for my self designed icons/images viewable in a separate pane in excalidraw
→ make a library where I can put (import) my already made images so I can reuse them, drag and drop
→ I have no knowledge of coding, of programming, or scripting. So it should be straightforward. I suggest a plugin or if not possible a written step by step manual.

Things I have tried

What have I already done?
→ watched video: https://www.youtube.com/watch?v=_OEljzZ33H8 : i don’t understand anything about coding and scripts. So this is useless for me.
→ searched the internet: found nothing useful
→ searched Dicord/obsidian-excalidraw community: i can’t get an overview of it. And every so-called solution names the same above-mentioned YouTube video.