Xcode for old Macbook Pro

[Dave Horsfall]

I think I've asked this question before, but I cannot find the response(s).
Where can I find Xcode for an oldish MacBook Pro (13", Mid 2010) running 
Sierra 10.12.6 (I've been told by the dealer that it cannot run High 
Sierra, and when I tried it on an older MacBook it was a disaster).

Thanks.

-- Dave