2D DWG in scale of 1:1

How to convert 2D drawing via 2D DWG in scale of 1:1? Since I have used free of charge version in April 2019, it was included. However when I joined the pakage of SketchUp Shop, the scale of 1:1 function is blocked in grey color. How and what can I do?

Thanks all for kindly assistance.

Is your view using Parallel Projection? Scaling in Perspective is irrelevant so it is greyed out.

Got it. Much appreciated the sharing.