Is it possible to set up approval route on budget and run it with the requisition approval route?

Summary:

We want to put a budgetary control when opening a requisition.

We made the all necessary setups for budgetary control on Setup and maintenance. When we try open a requestion after setup budgetary control, the requisition going the budgetary control before requisition approval routes.

I mean If there is not enough budget, we cant submit the requisition because It gives budgetary control error.

But our client does not want to use the budget control in this way.

Their request is as follows: if the requisition amount exceeds the budget, oracle fusion does not give us an error,

If there is a exceeded budget, It should go to the manager for approval. We actually want to set up an approval route for over budgetary control.