Hello, thanks for your reply.
I have received the following from my developer after passing on your solution.
“That code looks promising, but at the moment it’s returning the nickname of the currently logged in user (e.g. shops/admindave) instead of the nickname of the user in the result. I think the wp_get_current_user function needs changing to something else, but I’m not sure what’s returned in the results array.
Might be worth asking them to suggest an amendment.”
Thanks for your help