Since you mentioned that you are getting the OEM roof rails installed on your 2019 Honda Odyssey EX-L, all you'll need to attach your ARB 81444 Retractable Awning to your vehicle, is a set of cross bars.
I recommend going with the Thule WingBar Edge Crossbar # TH89RE, with the Edge Raised Rail Feet for Thule Edge Crossbars - Raised, Factory Side Rails # TH69SC.
This is a no drill installation, and will simply attach to your OEM roof rails.
These cross bars measure 60" long, and has a... view full answer...