Download Journey to USB stick from Lexus site

[AL100]

Has anybody ever managed to download a "Journey" created on the Lexus web site to a USB stick and then uploaded that into their car?  The Lexus website suggests that you can upload journeys either by sharing to the car over the internet or by downloading to a USB stick.  I only use a pay-as-you-go phone so I don't wish to connect my car to the internet with that but I would like to add journeys to the sat nav system via a USB stick.

I have tried various browsers with various operating systems - (Windows 10, Mac Catalina and Linux) - and I either get a blank page or an error message which says "This page isn't working, www.lexus.co.uk is currently unable to handle this request, HTTP error 500".  I have contacted Lexus with a question on this but having gone round the houses for ages they ended up advising me to visit my local Lexus centre to set up an internet connection via my multi media device - which is not what I was asking of course.  I used to do this sort of thing with my previous car, a BMW 3 series, and just wondered if anybody had ever got the Lexus system to work?