How can cut this shape frome the edege

1) make a surface as a copy of the existing solid face. Trim the surface to have the shape of the indentations you want to make. Use Cut>Thicken.

2) or make the shape of the indentations and use the Indent tool in a solid

3) or use the surface extrude function that everybody seems to have forgotten:

     - split out the faces you want to indent.

     - start the surface extrude command

     - select the faces of the indent

     - select a direction to extrude

     - add some draft,

     - use Cap End setting and Delete Original Faces and Knit Result options