I use a cheap bike mount like the one in the following link:

https://www.amazon.com/MBP-Alloy-Release-9x100mm-Storage/dp/B07MDXZGMB/ref=sxin_15_pa_sp_search_thematic_sspa?content-id=amzn1.sym.b245e49f-68a4-4489-b1f9-81f4034255f5:amzn1.sym.b245e49f-68a4-4489-b1f9-81f4034255f5&crid=GZI0HO0ZMI0J&cv_ct_cx=Delta+bike+mount&keywords=Delta+bike+mount&pd_rd_i=B07MDXZGMB&pd_rd_r=ca59e66c-2229-4b39-bf55-b2b6fb478a3e&pd_rd_w=bHCM2&pd_rd_wg=tLAAe&pf_rd_p=b245e49f-68a4-4489-b1f9-81f4034255f5&pf_rd_r=9T1JFW7GHWNT95NK124R&qid=1658671527&sprefix=delta+bike+mount,aps,121&sr=1-3-a73d1c8c-2fd2-4f19-aa41-2df022bcb241-spons&psc=1

I use a mount similar to the ones in this link to attach them to the crossbar:

https://www.westsubarudistributors.com/p/49924732/e361saj600.html?origin=pla&partner=googlebase&gclid=EAIaIQobChMI85X25dmR-QIVTfbjBx1mjQU8EAQYBSABEgK50fD_BwE

I have these attached to the cross bar and use two toe straps to strap the rear wheel to the other cross bar. It’s super simply and cheap. And sturdy. I only have two of these, but I bet you could get four on top of your Outback. It’s not going to have that Thule badge for everyone to see but it will get your bikes to trail head.

Edit: Looks like the cross-bar mounts in the second link are listed up to 2017 models but I’m sure you can find similar ones that will fit your stock cross bars.

This video guy made one out of wood. I think I would simply if by mounting some fork mounts like this instead.