Unwraping Problem

Hello I have been working on armored car model and now I only need to texture it, but when I try to unwrap I get this error “Object has non-uniform scale, unwrap will operate a non-scaled version of the mesh”. What to do? Thank you!

Look at the objects scale. You will see that you don’t have the same scale value for each axis (non uniform scale)
Select the object and apply the scale (Ctrl+A). The scale for each axis will now be 1