Greetings Johannesov, you've added some unnecessary things in to your model.
Delete Pad002
Delete Fusion (select Yes in the Object Dependencies pop-up window)
Delete Pad001
Delete Sketch001
Now you only have Sketch and Pad (which make up the cylinder) and Shapestring (the text) remaining.
Change to the Part (not Part Design) Workbench
Select Shapestring
Select the Extrude tool:
In the Direction area of the Extrude window change Y to 1, and change Z to 0.
Use 10 for length (units are mm)
Click the Apply button to see the result
Click the OK button to exit the Extrude command.
Now join the extruded text to the cylinder:
While still in the Part WB,
Select the Boolean tool:
On one pane select Extrude, in the other pane select Pad, make sure the Union radio button is selected, click Apply, then click Close.
If you like you can make another concave Pad on the outside of the cylinder and subtract Pad001 from Fusion with the Boolean tool again. (Fusion in the left pane, Pad001 in the right pane)
The file is too big to upload to the forum;
you can download it here.
(I'm too lazy tonight!)
FreeCAD
