Hi @Marko_Vukotic

There are multiple way of doing such a things, here are two of them

Using the Pen

You can use the Pen P to trace the global shape, Then add a fill color and smooth the angle thanks to the corner radius

Using two rectangles

1. Draw two rectangles R and place them above each other (as shown in your reference image).
2. Use the boolean operations > Union selection.
3. Then adjust corner-radius to smooth the angle
   
   

Hope it’ll help