In Purchase requisition (ME51N), how to change approver on workflow while saving it

Hi Guys,

I know there is user exit  EXIT_SAPLEBNF_001 where we can change the approver for the workflow, but  this user exit triggers only if the user goes to ‘RELEASE STRATEGY’ (RS) tab. What if the user does not go to this tab and straight press SAVE button. I tested, in this case the approver is not changed.

My requirement is to change the approver to the manager of the user, creating the PR.

Most of the time user does not go to RELEASE STRATEGY (RS) tab and they simply press SAVE to create the PR.

Any suggestion, how I can change the approver without going to RS tab.

Thanks a lot.