Logged into LATAM today to check on my old LANPASS miles. How do I book a BA flight from LCY to EDI? The website is confusing. Can I book one ways or does it have to be a roundtrip?

The message below was not helpful:

"You can redeem your LATAM Pass KMS. for flights with American Airlines, Qantas and Iberia through our Contact Center or at one of our offices. For other oneworld and associated airlines, this service is not available."