Editing items in draft PO

Hi, I have entered items and have created a PO and saved it. Currently in draft more.
I want to change some items (delete a few items and add new items) and I don’t see any such options in my PO.
Any help would be appreciated.

If your PO is still in draft u should be able to do all the required changes unless there is a work flow associated with PO process

What if the PO has been submitted. How can we amend it before any Purchase Receipt is carried out? Is cancelling the PO only option?

After submission u have to cancel and amend