No. Do not do that.

Shiplap isn't a rectangle in cross section. It has a notch taken out on the long sides on opposite sides so the boards fit together with no gap. You could use plain 1x4" or 1x6" boards if you were lucky enough to find good straight ones. That would be cheaper than real shiplap.

Thanks for the input everyone! Noted!

I do have the option to use actual planks. They are very thin. 1x4 and 1x6 available. They are pretty straight. I would have to use nails for cement to keep them into the wall. There is also the option for those ceramic tile ones that have wood texture.