I ordered them straight off of Amazon. Link below.
Super easy to install.
https://www.amazon.com/Tyger-Auto-TG-AM2C20248-Compatible-Silverado/dp/B07QFSP9H3/ref=mp_s_a_1_6?keywords=2019+silverado+running+boards&qid=1572903863&replacementKeywords=running+boards&sprefix=2019+silve&sr=8-6&vehicle=2019-47-491------------&vehicleName=2019+Chevrolet+Silverado+1500