Castrol Edge European Formula 5w30 A3/B4 is the stuff they make that carries the LL-01 rating
https://www.amazon.com/Castrol-03037-5W-30-Advanced-Synthetic/dp/B0161A4CKG/
They also make a 0w30 of it with the same ratings
https://www.amazon.com/Castrol-06244-0W-30-Advanced-Synthetic/dp/B007G7PUMS/
That being said, re: Walmart, they do totally sell the stuff https://www.walmart.com/ip/Castrol-EDGE-5W-30-A3-B4-European-Formula-Advanced-Full-Synthetic-5-Quarts/563245545
It's not that hard to find
I don’t know what’s up with Amazon, but it seems all of the European formula oils that are ideal for your application are “currently unavailable”. (Unless it doesn’t like that I’m from Canada for some reason.)
Mobil 1
https://www.amazon.com/Mobil-124044-Formula-Engine-Bottles/dp/B07QLJHLHN/
https://www.amazon.com/Mobil1-123875-Formula-Engine-quarts/dp/B07MXPNH7S/
Castrol Edge
https://www.amazon.com/Castrol-06244-0W-30-Advanced-Synthetic/dp/B007G7PUMS/
https://www.amazon.com/Castrol-06518-0W-40-Advanced-Synthetic/dp/B00BRLCC66/
https://www.amazon.com/Castrol-03101-0W-40-Advanced-Synthetic/dp/B00JGQLYP4/