[Tinkers' Complement] How do you open the Scorched Duct GUI?

I cannot for the life of me figure out how to use/configure the Scorched Ducts from Tinkers' Complement in my 1.12.2 world. Right-clicking them (placed or unplaced blocks, with or without shift) does nothing to configure them, nor does it open the GUI I've seen mentioned on several wikis. The interact key doesn't do it either. The in-universe manual barely mentions ducts, much less describes them. The way all my sources skim over configuring ducts suggests that it must be easy, but nothing I do works! I feel like I'm taking crazy pills here. Please help?