Dear Ahmed,
I think you will find this configuration under Allocation Structure you use it when settlement WBS.
you can change this configuration from:
SPRO--> Project System --> Costs --> Automatic and Periodic Allocations --> Settlement --> Settlement Profile --> Create Allocation Structure
after that select your allocation structure and go to Settlement cost elements
if By Cost element field flagged it mean that settlement with original cost element (settlement will be on the same cost element)
otherwise system will used the assign secondary cost element type 22
BR,
Amr Elsherif