Advanced Skill Selection system 1.21

I want to make it so plays with a scroll (carrot on a stick with tags) can use q and f to cycle through skills and right click to cast. (This part I mostly know how to do), But my main problem is I want it so you can pick which 6 abilities are on the scroll through some gui or chat stuff (I will use whatever is easier). Does anyone know how to make a system to select what 6 abilities are on the scroll?