Go to the search bar.
Tap the plus symbol in the upper right corner.
KAYA will ask "What's the type of climb?" Select the type.
Follow the prompts to fill in the climb's metadata, including grade, taxonomy, GPS location, and a description, then submit to finish adding it.
If you're adding a new wall specifically: tap "Add New" in the search bar on that page, then enter the GPS location for the wall.