Changing Currency in Requisitions for Peoplesoft

Hi teams,

I had User input Requisitions with IDR currency and the requisitions already saved and then when her line manager try to approve she ask the user to change the currency to USD.

So with requisition status still PENDING APPROVAL , user try to change the currency , however she can't save the requisition and there's pop up error.

Then I suggest to just delete the item in distribustion line, and re entry in another line, then the requisitions can be saved.

But when the line manager try to approve via worklist , the Currency and the amount is still in IDR. Why is that?