1-2-3 · noun1
1-2-3 · verb2
Possibly the three steps of riding a jeepney, from Tagalog sakay (“ride”), hintay (“wait”), alis (“leave”), wherein it notably lacks the step of paying for the fare. Another possible source is the saying of "1, 2, 3" before jumping off a jeepney without paying.
Etymology from Wiktionary, CC BY-SA 4.0.