You actually don't need a quest, although it does make it easier to access. If you go to the "Surface" layer you can add steps like so:
- Tap on a path to select it.
- If you need to select a smaller section, tap the 3 dots in the bottom left and select "Split Way".
- To make them steps, tap the 3 dots in the bottom left and tap "These are steps".
Why in gods name are we downvoting giveaways? Thanks for posting so I don't miss these.