I thought I heard something like maybe it was changed from blender 3 on but I’m not sure not sure how to do this task in blender… if somebody could help me with this I would appreciate it
Last release is 3.1.
In 3.1, Alt D is working and corresponding to duplicate linked.
I don’t recall such problem with 3.0.
The fact that you are not able to find it in search F3 menu, make me think that maybe, you are in the wrong mode.
To duplicate linked an object, you have to be in object mode.
You could be in vertex paint mode or sculpt mode without noticing a change in object appearance.
it worked!!! you were right