I see a blurb of text that says I can enter my backstory if I want, but there is nothing to click that actually lets me, you know... do that.

I'm weird, because I like writing out detailed backstories. All of these games let you do that. Baldur's Gate 1-2, NWN1... I once spent a whole "gameplay" session at the start of Icewind Dale 1 writing out little short stories for my full party of six, what they did in the past, how they came together, all of that. It's fluff, and it changes nothing mechanically, but I love doing it, and up until now the Enhanced Editions have all let me do it. Why not this one?