Sorry I haven't got one but I have lusted after one.
I do remember seeing some you tube videos on them and an American woman called Evy Hawkins who had written booklets (I think) on using the machines.  She has a web site called A Bit of Stitch and on there is a video of how to thread the machine so that may help.
I also kept this link in case I ever bought one.  It won't help with threading but should if you ever get started. https://www.quiltingboard.com/blogs/babylock-sashiko-machine-tips-reduce-thread-breakage-b13272.html

My local Smiths no longer has these on display.  I asked and they said that they can orfer it but are not getting copies to put on the stand.  Quite a few needle craft and quilting ones have disappeared off their shelves over the last few months.