Thanks for info on USB-C to Lightning cable not being correct cable. I was disappointed that I was incorrectly advised that I needed this cable when I ordered my Studio Design Display.
I do have the black thunderbolt cable that came with my Studio Design Display. It plugs easily at back of the Studio Design monitor in the marked thunderbolt port but it is impossible to fully insert the other end of it into any of the 4 ports on. my MacBook Pro (2017, 13" monitor). I do not see any other cable in the box that the monitor came in, but will look again.
I sure wish I could connect the new monitor up but will have to wait until I go to the Apple Store with my computer and the cables next Tuesday, unless you have more suggestions. It could be operator error on my part, but I tried my best to make connections without damaging cables and ports.