Change Appearance Icon Not Showing?

[unique basalt]

I have a lot of items in my Appearances Collections, but I've never seen the Change Appearance option in my Gear menu. I'm playing on a PC. How do I equip the Gear items I've collected?

[restive idol]

in the inventory, where all the pieces are, head, scarf, robe, etc, you hover over the one you wanna change and it'll say "blank button" change appearance", don't know what the button is, i played on controller on pc

[glass shell]

I think it is F, on PC

[cobalt rock]

Yeah, it's F.