I can't believe I need to make this issue, but you didn't actually say how to open the fucking GUI in game. There's nothing on Modrinth. This mod is completely useless to me as I have no idea how to actually use it. Also mods that use this crash the game when you try to open their config with Configured.

YACL only provided the screen, it doesn't set it. This means mods themselves have to make the screen accessible.

There are many different ways a mod can make its config screen accessible, most of the time you can access the screen through the configure button in the mod list.

About the crash, what modloader and minecraft version are you using?