3819141 - Why is the Can Approve option missing when adding an Expense Delegate?

I have a list of delegates that must be able to create, submit and approve expense reports. When I try to assign these delegates the necessary permissions to do the above tasks, I don’t see an option to let them approve reports. The ‘Can Approve’ option is missing. Why?

I want the delegates to be able to approve expense reports, but I’m missing this option in the list of permissions available , KBA , CON-CA-ADM , Administration , Problem