You should be able to simply add the second WiFi details. The Move would then find the stronger signal.

Note that if it’s the repeater type of extender -- as opposed to a wired access point -- it’s not officially supported, but it may work okay.

Ok, thanks for the reply.

I can see the TP link extender on my iPhone under the settings/WiFi option - it has the same name as normal network but with a suffix of EXT added. If I connect to this network on my iPhone then I can control my SONOS Move. Yet when I look at “networks” on the Sonos app it only shows the original network (not the extended). So how do I know if the Sonos is actually ,asking use of the tp link extender? And it isn’t, then is it possible to add it as an option? I can’t see it listed anywhere in the Sonos app. 
 

thanks

If it’s not listed in Setting/System/Network then the details aren’t stored in the system. Use Wireless Setup to add the extra set.